ROTO HYDRA-MATIC

Since Oldsmobile’s Y-body compact, the F-85/Cutlass, shared the same basic V8 engine block as the Special (albeit with different cylinder heads and air cleaner), the same three-speed manual transmission, and even the same driveshaft, it would have made sense for the two cars to also share the same automatic transmission. Instead, Oldsmobile opted for a scaled-down version of Detroit Transmission Division’s latest, third-generation Hydra-Matic.

For the sake of clarity, we’ll describe the third-generation Hydra-Matic as “Roto Hydra-Matic,” which is what Pontiac called the transmission in 1963 and 1964; most users simply called it “Hydra-Matic.” (Confusingly, Oldsmobile used the trademark “Roto-Matic” for power steering!) There were actually two different versions of the new transmission: The standard Model 375 (aka Type 61-10) unit was used in full-size Oldsmobiles and some full-size Pontiacs. The light-duty Model 240 (aka Type 61-5) was optional on the Y-body Oldsmobile F-85/Cutlass and on GM’s senior Australian, German, and English cars: the EK (and later EJ) Holden Special, the Opel Kapitän L, and Vauxhall Cresta. The Model 375 was 29 lb (13 kg) heavier than the smaller version, had greater torque capacity, and used fractionally taller (lower numerical) indirect ratios.

Judging by the relevant patent disclosures (U.S. Patents 3,141,354 and 3,132,535), Roto Hydra-Matic was developed by some of the same engineers responsible for the four-speed Controlled Coupling Hydra-Matic, including Walter B. Herndon (with Howard E. Olsen) and August Borman, Jr. (with Charles W. Cline and Carl E. Shellman). The production transmission is typically credited to Detroit Transmission’s assistant chief engineer, Jack W. Qualman, and his boss, Jack R. Doidge. In any case, the new transmission’s conceptual relationship to earlier Hydra-Matics remained evident, although it borrowed a few concepts from the triple-turbine transmissions as well.

Compared to its immediate predecessor, Roto Hydra-Matic was lighter, more compact, and mechanically simpler. There were now only three forward speeds rather than four; two planetary gearsets rather than the previous three; and a single three-element torque converter rather than two fluid couplings. The front overrun clutch and sprag brake were deleted, as was the rear oil pump. The previous neutral clutch was retained, as were the rear overrun band and the reverse cone clutch, although the latter was now part of the front gearset. There was also a new multi-disc front clutch, located between the front unit annulus and the torus cover.

Roto Hydra-Matic’s two planetary gearsets were interconnected by three concentric shafts. The main shaft, innermost of the three, connected the torque converter turbine to the rear gearset sun gear through a vibration damper, a steel-jacketed, splined rubber cushion designed to damp torsional vibrations and keep the main shaft splines from rattling. Around the main shaft was the carrier shaft, which connected the planet carriers of both gearsets to the torque converter’s reaction member and the transmission output shaft. Surrounding the main shaft was a hollow sleeve shaft that linked the reaction members of the two gearsets — the front sun gear and rear annulus — to a single centrally mounted sprag clutch that would hold both elements stationary in first and second gears. The overrun band, which surrounded the the rear annulus, could be engaged to do the same thing. (On the light-duty 61-5 model, both the sprag clutch and overrun band were replaced by a double-wrap brake band, which was engaged in first and second gear and released in third; eliminating the sprag clutch also allowed the deletion of the neutral clutch, since the brake band was completely released in reverse and neutral.)

Interconnecting the two gearsets in this manner meant that their ratios couldn’t be compounded as in earlier Hydra-Matics, which is why Roto Hydra-Matic had only two indirect ratios rather than three. (In fact, the interconnection of the planet carriers meant that putting one gearset in reduction effectively put the other in overdrive, although the overdriven member simply spun idly.) Power flowed through the rear gearset in first and the front gearset in second.

Even more unusual was the torque converter. Derived from the Controlled Coupling Hydra-Matic’s smaller second coupling, it was similar in size — diameter was only 8 inches (203 mm) — and retained the earlier coupling’s dump-and-fill capacity and straight impeller and turbine blades. Nestled within a cutout section of those blades around the converter hub was the converter’s third element: a 22-vane torque multiplier that Oldsmobile marketing pithily dubbed the “Accel-A-Rotor.” The Accel-A-Rotor was not a stator in the customary sense; since it was splined to the carrier shaft, it always rotated at the same speed as the driveshaft and could turn in either direction.

To avoid impairing converter efficiency at cruising speeds, the torque multiplier provided a nominal stall ratio of only 1.30:1. In practice, torque multiplication was both more and less than that modest figure. As explained on page 2, during torque multiplication, oil leaving the turbine exerts reaction torque on the stator. Unlike a conventional stator, Roto Hydra-Matic’s torque multiplier applied that reaction torque directly to the carrier shaft and would actually turn backward if the car was moving in reverse. In principle, that allowed the torque multiplier to function as an auxiliary turbine, although the practical effect was just a small amount of extra leverage in reverse that increased the effective stall ratio to 1.42:1 in that gear. In first, however, the reaction torque on the Accel-A-Rotor resisted the carrier shaft’s forward rotation, reducing the converter’s effective stall ratio to a meager 1.20:1.

Unlike earlier Hydra-Matics, the impeller of Roto Hydra-Matic’s torque converter was driven by the torus cover in more or less conventional fashion and therefore always rotated at engine speed. The converter housing was always full in Park, neutral, first gear, and reverse, enabling the engine to idle without stalling and providing extra torque multiplication when starting. When idling in any forward drive range, the neutral clutch was engaged and the front clutch was disengaged, so Roto Hydra-Matic would always start in first. On the Model 10, moving the selector to Low or S/D-Right, the overrun band would also engage to keep the reaction members locked when coasting; the band wasn’t used at all in normal D/D-Left range. (The Model 5, which didn’t have a sprag clutch, simply left the brake band engaged in those ranges.)

For the 1–2 shift, the torque converter’s oil supply was rapidly emptied; all three elements continued to rotate, but with no working fluid to move, they had no effect. As the converter drained, the front clutch engaged, allowing the torus cover to simultaneously drive the impeller and the annulus of the front gearset. (With the selector in Low, the transmission could not shift into second.) In a panic stop, cut-off valves in the hydraulic control system would quickly refill the converter and disengage the front clutch so the engine wouldn’t stall when the car came to a halt.

For the 2–3 shift, the torque converter was refilled, reestablishing the hydraulic connection between the turbine and the rear sun gear, but this time the front clutch remained engaged. That unlocked the sprag clutch and allowed both gearsets to turn together in direct drive (or near enough). (In S/D-Right range, the shift to third would also automatically release the overrun band; on the lighter 61-5 transmission, which had no sprag clutch, the brake band released on the shift to third.) In third, torque was split three ways: through the front clutch to the front annulus; through the converter turbine to the rear sun gear; and through the torque multiplier to the carrier shaft.

Discounting the unusual behavior of the torque multiplier, reverse functioned much the same way as in earlier Hydra-Matics. Moving the selector to Reverse disengaged both the front clutch and the neutral clutch (or brake band) while engaging the reverse cone clutch to lock the front annulus. The torque converter drove the rear sun gear, just as in first, but with the neutral clutch now released to neutralize the sprag clutch (or, on light-duty models, with the brake band released), the rear sun gear drove the rear annulus — and with it the front sun gear — backward. The stationary front annulus served as a reaction member, causing the driven planet carrier — and thus the carrier shaft and driveshaft — to rotate backward in reduction.

The following table summarizes the shift sequence for the full-size Roto Hydra-Matic. (Again, “REL” = “RELEASED” and “ENG” = “ENGAGED”; you can probably guess that “Torque Conv.” = “Torque Converter.”)

Like its predecessors, Roto Hydra-Matic placed Reverse at the far end of the shift pattern, adjacent to Low, and allowed the car to be “rocked” by moving the selector back and forth between Low and Reverse. A reverse blocker (theoretically) prevented the transmission from going into reverse if the car was moving faster than a crawl. However, as with Dual-Path Turbine Drive, there was no longer any provision for push-starting. The single oil pump was now driven directly off the engine flywheel, so neither could be driven by the propeller shaft with the engine off.

Roto Hydra-Matic was even smoother than the four-speed Controlled Coupling Hydra-Matic, but a certain amount of performance was sacrificed in the process. In fact, many contemporary reviewers judged the three-speed Hydra-Matic in the Oldsmobile F-85 inferior to the two-speed Dual-Path Turbine Drive used in the Buick Special or even Powerglide in both performance and shift quality. Part of the problem was that Roto Hydra-Matic’s shifts were now quite slow. The adoption for 1962 of a new hydraulic pressure control system allowed shift speed and firmness to vary with engine torque, which helped some, but the assertive shift quality that was once a Hydra-Matic hallmark was now long gone.

A bigger issue, so far as performance was concerned, was that the three-speed transmission’s ratios (listed in the table below) were far from ideal. Despite the torque multiplier and a rather short first gear, starting ratios were still taller than the four-speed unit’s. That wouldn’t have been so bad, but Roto Hydra-Matic’s second and third gears were closer to third and fourth in the dual-coupling Hydra-Matic, leaving a big gap between first and second that the torque multiplier (which was ineffective once the car was in motion) could not plug. The annoyance of the ratio gap was compounded by the hydraulic control system’s frustrating tendency to vacillate between second and third.

Another unhappy peculiarity was a penchant for oil leaks. We don’t know all the factors that may have contributed to that problem, although we wonder if it was partly related to Roto Hydra-Matic’s operating pressures, which were generally higher than with its four-speed predecessor and may have tested the integrity of the seals. Particularly noteworthy is the fact that converter charging pressure was quadrupled (to 180 psi/12.41 bars) to make up for the torque capacity sacrificed to the torque converter’s diminutive size. We assume the rationale for the small diameter was, as before, to facilitate rapid drainage and refilling. The dilemma, of course, was that the dump-and-fill coupling in the earlier Controlled Coupling Hydra-Matic never had to bear more than 40% of input torque; Roto Hydra-Matic’s torque converter had to bear the full engine output in first gear.

The good news was that the new layout, along with a switch from cast iron to aluminum for the transmission case, made Roto Hydra-Matic — soon nicknamed “Slim Jim” — more compact and some 75 to 95 lb (34 to 43 kg) lighter than the dual-coupling Hydra-Matic (which remained in production for Cadillac and some Pontiacs). It was also cheaper to build, if not to buy.

(To the latter point, we should note that while the list prices of automatic transmissions had crept steadily upward since the forties, that inflation had been at a somewhat slower rate than the inflation in new car prices. Thus, while automatic transmissions weren’t getting any cheaper, the price of the option as a percentage of the cost of a new car had actually decreased.)

THE END OF THE LINE

By the mid-sixties, the autonomy GM had long allowed its individual automotive divisions was beginning to give way to a new emphasis on inter-divisional commonality. We don’t know if the Y-body compacts represented some kind of breaking point in that regard, but we wouldn’t be surprised. Their development and manufacturing costs had been high — higher, we have little doubt, than most of GM’s contemporary full-size cars, and largely concentrated in areas that the average buyer wouldn’t even notice — and sales had been disappointing, which was a recipe for lackluster profits.

During this period, GM began a belated move toward standardized transmissions. Having multiple automatic transmissions probably seemed reasonable when Buick was selling more cars than Plymouth and half the industry used Hydra-Matic, but the market downturn and various missteps of the late fifties and early sixties made the proliferation of sui generis transmissions seem like economic folly. The three-year production total for Dual-Path Turbine Drive, for example, was well short of the average annual volume of the early-fifties Hydra-Matic. Numbers like that made it harder to justify the R&D and tooling costs of multiple transmission designs.

GM initially opted for a two-pronged approach: a new two-speed automatic for Buick, Oldsmobile, and Pontiac A-body intermediates, which replaced the Y-body compacts for 1964, and a new three-speed transmission to replace the Roto Hydra-Matic and Controlled Coupling Hydra-Matic in bigger cars. Chevrolet, whose annual production generally exceeded the combined totals of the other four automotive divisions, continued to build and use its own two-speed Powerglide.

The new transmissions were developed by engineers from the corporate transmission group and Detroit Transmission Division, which was formally renamed Hydra-Matic Division on October 1, 1963. The two-speed, which Buick called Super Turbine 300 (ST-300) and Oldsmobile called Jetaway, was mechanically very similar to the aluminum-case Powerglide, using a Ravigneaux gearset to provide indirect ratios of +/-1.765:1. The three-speed unit was the Turbo Hydra-Matic 400 (TH-400), which Buick called Super Turbine 400 (ST-400), an all-new design using a licensed version of Howard W. Simpson’s patented “Simpson gearset“: two planetary gearsets sharing a single common sun gear. Both transmissions had three-element torque converters and used a new type of vacuum modulation.

Some sources — including contemporary Buick publicity and marketing material — suggest a lineal connection between these transmissions and the earlier Dynaflow/Turbine Drive, Dual-Path, and Hydra-Matic units they replaced, which was really only true in certain broad or incidental ways. Gone for good were the multiple turbines, dump-and-fill couplings, and split torque clutches (although Turbo Hydra-Matic would eventually add a lockup torque converter clutch in the pursuit of better fuel economy). The one exception was that some 1964–1967 ST-300/Jetaway and 1965–1967 ST-400/TH-400 transmissions used a two-position variable-pitch stator, similar in principle to the one Dynaflow had first adopted back in 1955. However, the pitch angles were different and the stator servo control valve was now operated by a solenoid triggered by the kickdown switch. Pontiac and Chevrolet never used the “switch-pitch” stator, nor did Series Seventy-Five Cadillacs; other users deleted the feature after the 1967 model year.

The new two-speed automatic was first offered on the 1964 A-body Buick Special/Skylark, Oldsmobile F-85/Cutlass, and Pontiac Tempest/Le Mans/GTO and the B-body Buick LeSabre and Oldsmobile Jetstar 88. At the same time, Turbo Hydra-Matic replaced Turbine Drive on full-size Buicks (including the Riviera) and superseded the four-speed Hydra-Matic on the Cadillac DeVille, Sixty Special, and Eldorado. All remaining U.S. users of both earlier Hydra-Matics switched to TH400 for the 1965 model year. In mid-1965, Chevrolet also began offering Turbo Hydra-Matic as an option for full-size cars equipped with the new 396 cu. in. (6,488 cc) “Turbo Jet” engine. Turbo Hydra-Matic became available on certain A-body intermediates for 1967 and on the Corvette for 1968.

By the late sixties, two-speed automatics were becoming increasingly anachronistic, so the ST-300/Jetaway was relatively short-lived. Starting in 1969, both ST-300/Jetaway and Powerglide were phased out in favor of scaled-down, medium- and later light-duty versions of Turbo Hydra-Matic. Two-speed automatics had disappeared from all of GM’s North American cars by the 1974 model year.

The mechanics and further development of Turbo Hydra-Matic (sometimes styled “Turbo Hydra-matic” or “Turbo-Hydramatic”) are beyond the scope of this article, but suffice to say it was a very successful and generally well-regarded line. Like the old four-speed Hydra-Matic, the TH400 was also used by a variety of outside automakers, including Rolls-Royce and Bentley, Jaguar, and even Ferrari.

In 1983, GM chairman Roger Smith ordered the consolidation of all the corporation’s transmission plants under the control of Hydra-Matic Division, eliminating the last vestiges of the old divisional rivalry. In the early nineties, GM created GM Powertrain by combining Hydra-Matic Division with GM Engine and later the Central Foundry Division and the Advanced Engineering Staff, the heirs of the group that originally developed Hydra-Matic and Dynaflow.

Since 2010, the GM Powertrain group has been part of the larger Global Products Operations organization, although the Hydra-Matic name is still in use — and of course remains a registered trademark of General Motors. Modern Hydra-Matic transmissions, however, bear only a faint resemblance to their pioneering and sometimes peculiar forebears.

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AUTHOR’S NOTE

The author would like to offer special thanks to reader Dave Ostroska for generously providing us with a copy of the factory service manual for the Buick Dual-Path Turbine Drive, which is now quite hard to find.

NOTES ON SOURCES

Information on the development of Dynaflow, Powerglide, and Dual-Path Turbine Drive and their antecedents (including Buick’s earlier IV “Roller” friction drive) came from William C. Anderson, “Charles A. Chayne, Buick’s Unsung Hero,” The Buick Bugle September 2003, www.buickheritagealliance. org/ pdf/ chayne.pdf, accessed 20 May 2010; Ray T. Bohacz, “Mechanical Marvels: Smooth Operator: Buick’s Dynaflow Automatic Transmission,” Hemmings Classic Car #77 (February 2011), pp. 70–72; Griff Borgeson, “Buick Has Looks, Plus Ride at Moderate Price,” Motor Trend Vol. 3, No. 10 (October 1951), reprinted in Buick Performance Portfolio 1947-1962, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2000), pp. 25-27, and “Road Test: Buick’s New Century,” Motor Life April 1954, reprinted in ibid, pp. 44–47; Arch Brown, “High-Fashion Hauler: 1948 Buick Roadmaster Estate Wagon,” Special Interest Autos #136 (July-August 1993): pp. 12–19, 62–63; “Out Front Again! 1950 Chevrolet Bel Air,” Special Interest Autos #108 (November-December 1988), reprinted in The Hemmings Book of Postwar Chevrolets: driveReports from Special Interest Autos magazine, eds. Terry Ehrich and Richard Lentinello (Bennington, VT: Hemmings Motor News, 2001), pp. 4-10; “SIA comparisonReport: 1954 vs. 1955 Chevrolet,” Special Interest Autos #100 (July-August 1987), reprinted in ibid, pp. 36–44; “SIA comparisonReport: Upper Middle Class ‘Class’: 1948 Buick Roadmaster, 1948 Chrysler New Yorker,” Special Interest Autos #167 (September-October 1998), reprinted in The Hemmings Book of Buicks: driveReports from Hemmings Special Interest Autos magazine, eds. Terry Ehrich and Richard Lentinello (Bennington, VT: Hemmings Motor News, 2001), pp. 24–33; Buick Motor Division of General Motors Corporation, “Buick’s Greater Cars in 50 Great Years” [brochure 500M], January 1953; “Buick ’60: Portfolio of Fine Cars” [brochure, ca. Oct. 1959]; “Buick takes the bows for ’48” [brochure], April 1948; “For 1957: Newest Buick Yet” [brochure, ca. October 1956]; “Front and Center for 1952 — Buick” [brochure, ca. 1952]; “Full Size 1961 Buick” [brochure, ca. 1961]; “1955 Buick: Forefront of fashion—Thrill of the year” [brochure], 1955; 1955 Buick Shop Manual (Flint, Michigan: 1955); “1956 Buick carries the banner forward” [brochure], 1956; 1961 Buick Special Service Manual BPS 1.51 (Flint, MI: Buick Division of General Motors Corporation, 1961); 1953 Buick Owner’s Guide, Third Ed. (Flint, MI: Buick Motor Division of General Motors Corporation, 1953); “Special: The Happy Medium-Size Car!!!” [brochure], 1962; “The Air Born [sic] B-58 Buick” [brochure, ca. October 1957]; “The Car: Buick ’59” [brochure, ca. Oct. 1958]; “The New Special Size 1961 Buick Special” [brochure, ca. October 1960]; “The trim-size Buicks for ’63” [Special/Skylark brochure, ca. October 1962]; and Variable Pitch Dynaflow, Second Edition (Flint, MI: Buick Motor Division, General Motors Corporation, 1955); “Buick Stories by Phil,” Buick Street, 2005, www.buickstreet. com/ buickstories.html, accessed 1 December 2015; “Buick Toe the Line,” The Autocar 3 February 1956, reprinted in Buick Performance Portfolio 1947-1962, p. 54; “Car Life Road Test: Buick Invicta,” Car Life Vol. 9, No. 11 (December 1961), reprinted in ibid, pp. 128–131; Charles S. Chapman and Rudolph Gorsky, “The Dual Path Turbine Drive,” The SAE Journal Vol. 69, No. 4 (April 1961), pp. 80–83; Charles A. Chayne, “Buick’s Dynaflow Drive,” The SAE Journal Vol. 56, No. 4 (April 1948), pp. 23–29; Chris Chant, “M18 Hellcat – The USA’s primary tank destroyer of WWII,” 10 July 2013, www.cmchant. com/ m18-hellcat-the-usas- primary-tank-destroyer-of-wwii, accessed 20 September 2015; “Chevrolet Impala Super Sport 409 V-8 with Powerglide,” Car Life Vol. 11, No. 2 (March 1963), reprinted in Impala & SS Muscle Portfolio 1958–1972, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1996), pp. 42–46; Chevrolet Motor Division of General Motors Corporation, “Chevrolet for 1961” [brochure, ca. October 1960]; “New Chevy II” [brochure, ca. October 1961]; Chevrolet 1950–1953 Powerglide Automatic Transmission Repair Manual (Detroit, MI: General Motors Corporation, 1952); Chevrolet 1950 Engineering Features: Passenger Cars (Detroit, MI: General Motors Corporation, 1949); 1953 Engineering Features: Passenger Cars (Detroit: General Motors Corporation, December 1952); “1962 Chevrolet” [brochure, ca. October 1961]; Servicing the Powerglide Transmission: Maintenance, Adjustment, Removal, and Installation (MTS Release No. 50-1), (Detroit, MI: General Motors Corporation, 1950); “’63 Chevrolet” [brochure, ca. October 1962]; “The 1954 Chevrolet” [brochure, ca. October 1953]; and Technical Service Department, Aluminum-Case Powerglide Training Program Booklet (TP-21), April 1962; Chevrolet Engineering Center, Engineering Product Information Department, 1958 Chevrolet Passenger Car Engineering Features (Warren, MI: October 1957), and 1959 Chevrolet Passenger Car Engineering Features (Warren, MI: October 1958); “Chevrolet Nova 396 SS [sic] Coupe,” Road Test July 1970, reprinted in Chevy II · Nova & SS Muscle Portfolio 1962–1974, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1995), pp. 102–107; “Chevvy [sic] Gets a Torque Converter,” Popular Science Vol. 156, No. 2 (Feb. 1950), p. 141; “Chevy II (Car Life Road Test),” Car Life Vol. 10, No. 1 (February 1962), reprinted in Chevy II · Nova & SS Muscle Portfolio 1962–1974, pp. 10–15; Floyd Clymer, “The Owners Report on the ’53 Buick V 8,” Popular Mechanics Vol. 99, No. 6 (June 1953), pp. 118–122, 230–242; Chris Conners, The AFV Database, “Armored Utility Vehicle M39,” 21 June 2015, afvdb.50megs. com/usa/auvm39.html, accessed 13 October 2015; “Medium Tank M26 Pershing,” 27 August 2015, afvdb.50megs. com/usa/ m26pershing.html, accessed 13 October 2015, and “76mm Gun Motor Carriage M18,” 21 June 2015, afvdb.50megs. com/usa/ m18hellcat.html, accessed 13 October 2015; “Curtice, Harlow – Generations of GM,” GM Heritage Center (n.d., history. gmheritagecenter. com, accessed 20 May 2010); Harry Cushing, “Buick Roadmaster,” Motor Trend Vol. 3, No. 11 (November 1951), reprinted in Buick Performance Portfolio 1947-1962, pp. 30–32, 71; Eric Dahlquist, “Camaro Two-Step,” Motor Trend Vol. 20, No. 7 (July 1968), pp. 64–65; “Transmission,” U.S. Patent No. 2,968,197, filed 14 March 1958, issued 17 January 1961; Jim Donnelly, “Eminent Domain,” Hemmings Classic Car #43 (April 2008), pp. 26–29, and “Rain Man Ryan’s Ride,” Hemmings Classic Car #61 (October 2009), pp. 14–17; Terry B. Dunham and Lawrence R. Gustin, The Buick: A Complete History (An Automobile Quarterly Magnificent Marque Book) (Kurtztown, PA: Automobile Quarterly, 1980); Jim Dunne and Jan P. Norbye, Buick 1946-1978: The Classic Postwar Years, Second Edition (Osceola, WI: MBI, Inc./Motorbooks International, 1993); David Edwards, Antique Automatic Transmission Parts, www.autotran.us; Devon Francis, “New Buick Flows from Low to High,” Popular Science Vol. 152, No. 2 (February 1948), pp. 113–118, and “What You Should Know About Automatic Drives,” Popular Science Vol. 156, No. 4 (April 1950), pp. 99-105; Joseph Geschlin, “Making the Dynaflow—An Exacting Precision Job,” Automotive Industries Vol. 98, No. 9 (May 15, 1948), pp. 26–27, 88–91; the GM Heritage Archive (gmheritagecenter. com/ gm-heritage-archive/); Philip G. Gott, Changing Gears: The Development of the Automotive Transmission (SAE Historical Series) (Warrendale, PA: Society of American Engineers, 1991); Winfield D. Gove and John Dolza, assignors to General Motors, “Torque Loading Lash Adjusting Device for Friction Roller Transmissions,” U.S. Patent No. 2,030,203 A, filed 31 May 1934, issued 11 February 1936; T. Grace, Automatic Transmission Service Guide (Union, NJ: Lincoln Technical Institute, September 1966); John Gunnell, ed., Standard Catalog of American Cars 1946-1975 Revised 4th Edition (Iola, WI: Krause Publications, 2002), and Standard Catalog of Buick 1903-2004 Rev. 4th Ed. (Iola, WI: Krause Publications, 2004); Gilbert K. Hause, assignor to General Motors Corporation, “Transmission,” U.S. Patent No. 3,108,493, filed 6 November 1958, issued 29 October 1963; “Split Torque Transmission,” U.S. Patent No. 3,039,325, filed 29 November 1960, issued 19 June 1962; and “Multiple Speed Split Torque Transmission,” U.S. Patent No. 3,084,569, filed 24 July 1961, issued 9 April 1963; Gilbert K. Hause and Oliver K. Kelley, assignors to General Motors Corporation, “Multi-Phase Transmission,” U.S. Patent No. 3,062,074, filed 19 February 1958, issued 6 November 1962; “How the New Buick Century Performs,” Science and Mechanics June 1954, reprinted in Buick Performance Portfolio 1947-1962, pp. 40–41; Roger Huntington, “The Great Transmission Controversy: Coupling vs. Converter,” Car Life Vol. 10, No. 2 (March 1962), pp. 18-25; “Is Buick’s 50th Year Its Best?” Motor Trend Vol. 5, No. 7 (July 1953), reprinted in Buick Performance Portfolio 1947-1962, pp. 33–36; Oliver K. Kelley, assignor to General Motors Corporation, “Combination Fluid Turbo Clutch and Variable Speed Gearing,” U.S. Patent No. 2,176,138, applied 5 February 1937, issued 17 October 1939; “Fluid Flywheel Gearing Arrangement,” U.S. Patent No. 2,211,233, applied 10 April 1939, issued 13 August 1940; and “Transmission Drive,” U.S. Patent No. 2,377,696, filed 15 December 1941, issued 5 June 1945; “Compound Power Transmission,” U.S. Patent No. 2,433,052, filed 6 September 1943, issued 23 December 1947; “Combined Transmission,” U.S. Patent No. 2,606,460, filed 29 November 1944, issued 12 August 1952; “Tank Cross Drive for Steering by Variable-Speed Ratio Driving Means,” U.S. Patent No. 2,585,790, filed 16 April 1945, issued 12 February 1952; “Fluid Drive and Controls,” U.S. Patent No. 2,625,056, filed 14 September 1946, issued 13 January 1953; “Rotary Hydraulic Torque Converter,” U.S. Patent No. 2,687,616, filed 11 January 1949, issued 31 August 1954; “3-Phase Turbine Drive,” U.S. Patent No. 2,737,061, filed 19 November 1949, issued 6 March 1956; “Fluid Control for Rotary Turbine Type Hydraulic Torque Converters,” U.S. Patent No. 2,638,746, filed 30 November 1949, issued 19 May 1953; “Dual Range Plural Turbine Gear Drive,” U.S. Patent No. 2,766,641, filed 8 November 1950, issued 16 October 1956; “Multiple Rotor Converter Having Plural Impellers,” U.S. Patent No. 2,727,360, filed 23 November 1951, issued 20 December 1951; “Hydrodynamic Torque Converter and Gearing,” U.S. Patent No. 2,782,659, filed 18 June 1952, issued 26 February 1957, reissued 14 March 1961; “Four Phase Converter Drive,” U.S. Patent No. 2,803,974, filed 5 August 1953, issued 27 August 1957; “Four Phase Converter Drive,” U.S. Patent No. 2,981,124, filed 5 August 1953, divided 25 April 1957, issued 25 April 1961; “Hydrodynamic Torque Converters and Controls Therefor,” U.S. Patent No. 2,999,400, filed 13 January 1954, issued 12 September 1961; “Hydrodynamic Torque Converters,” U.S. Patent No. 2,910,832, filed 22 July 1954, issued 3 November 1959; “Transmission,” U.S. Patent No. 2,821,095, filed 19 October 1955, issued 28 January 1958; “Hydraulic Torque Converter,” U.S. Patent No. 2,882,684, filed 17 July 1956, divided 31 July 1957, issued 21 April 1959; “Transmission,” U.S. Patent No. 2,882,751, filed 17 July 1956, divided 31 July 1957, issued 21 April 1959; “Hydrodynamic Torque Converters,” U.S. Patent No. 3,025,720, filed 26 March 1958, issued 20 March 1962; “Transmission,” U.S. Patent No. 3,030,823, filed 11 July 1957, issued 24 April 1962; and “Transmission,” U.S. Patent No. 3,242,677, filed 29 September 1955, issued 29 March 1966; Oliver K. Kelley and Gilbert K. Hause, assignors to General Motors Corporation, “Multi-Phase Torque Converter,” U.S. Patent No. 2,957,370, filed 11 July 1957, issued 25 October 1960; Oliver K. Kelley and John D. Lindsay, assignors to General Motors Corporation, “Multiple Stator Torque Converter,” U.S. Patent No. 3,025,719, filed 28 December 1954, issued 20 March 1962; Oliver K. Kelley and Robert S. Plexico, assignors to General Motors Corporation, “Transmission Control System,” U.S. Patent No. 2,865,227, filed 4 June 1952, issued 23 December 1958; Oliver K. Kelley and Robert M. Schaefer, assignors to General Motors Corporation, “Composite Fluid and Gear Drive,” U.S. Patent No. 2,782,658, filed 18 January 1951, issued 26 February 1957; Oliver K. Kelley and William S. Wolfram, assignors to General Motors Corporation, “Rotary Hydraulic Torque Converter with Dynamic Braking,” U.S. Patent No. 2,651,918, filed 30 July 1949, issued 15 September 1953; Carroll K. Lenning, assignor to General Motors Corporation, “Transmission Drive Cooling System,” U.S. Patent No. 2,270,536, filed 17 February 1940, issued 20 January 1942; Jim Lodge, “’55 Buick Roadmaster Special,” Motor Trend Vol. 7, No. 7 (July 1955), reprinted in Buick Performance Portfolio 1947-1962, pp. 50–53, 71 “’56 Buick Special and Century,” Motor Trend Vol. 8, No. 6 (June 1956), reprinted in ibid, pp. 56-59, and ; Joseph Lowrey, “Dynaflow Drive in the Alps,” The Motor 20 April 1949, reprinted in ibid, pp. 14-18; “M18 Hellcat Tank Destroyer,” n.d, m18hellcat. com/m18hellcat/ Home.html, accessed 20 September 2015; L.H. Nagler, “How Your Car Shifts for Itself,” Popular Mechanics Vol. 89, No. 5 (May 1948), pp. 102–106, 264, 268, 272; Chuck Nerpel, “Buick Invicta,” Motor Trend Vol. 12, No. 6 (June 1960), reprinted in Buick Performance Portfolio 1947-1962, pp. 100–104; “New Dynaflow Buicks,” The Motor 8 December 1948, reprinted in Buick Performance Portfolio 1947-1962, pp. 10–13; Paul Niedermeyer, “Powerglide: A GM’s Greatest Hit or Deadly Sin?” Curbside Classic, 30 March 2012, www.curbsideclassic. com/automotive-histories /powerglide-gms-greatest-hit-or-deadly-sin/, last accessed 4 January 2016; “1951 Chevrolet,” Special Interest Autos #17 (June-July 1973), reprinted in The Hemmings Book of Postwar Chevrolets, pp. 12–17; the Old Car Brochures website (oldcarbrochures.org); the Old Car Manual Project (www.oldcarmanualproject. com); “Packard’s Ultramatic Drive,” Product Engineering July 1949, reprinted in Packard Gold Portfolio 1946-1958, pp. 22–24; Robert S. Plexico and Russell E. Kaufman, “Chevrolet’s Automatic Transmission, The SAE Journal Vol. 58, No. 3 (March 1950), pp. 27–33; Jim Potter, “’54 Buick Special,” Motor Trend Vol. 6, No. 10 (October 1954), reprinted in Buick Performance Portfolio 1947-1962, pp. 42–43; “Road & Track Road Test: Buick Special V-6,” Road & Track Vol. 11, No. 3 (November 1961), reprinted in Buick Performance Portfolio 1947-1962, pp. 124-127; “Road Test: Buick Century,” Motor Life March 1955, reprinted in ibid, pp. 48–49, 63; “Road Test: The Buick V-8,” Motor World 22 May 1953, Buick Performance Portfolio 1947-1962, pp. 37–38; “Road Test: The Invicta and the Special,” Motor Life January 1961, reprinted in ibid, pp. 112-119; “Road Test – The 1956 Buick Century,” Motor Life May 1956, reprinted in ibid, pp. 60–61; Maurice S. Rosenberger, “Transmission Control System,” U.S. Patent No. 2,766,639, filed 8 November 1952, issued 16 October 1956, reissued 5 June 1962; Christian Seabaugh, “1944 Buick M18 Hellcat Tank Destroyer First Drive: Seek, Strike, Destroy!” Truck Trend 28 October 2013, www.trucktrend. com, accessed 20 September 2015; Wilbur Shaw, “Buick Hooks New V-8 to Dynaflow+Gears,” Popular Science Vol. 162, No. 2 (February 1953), pp. 159–162, 248; Don Sherman, “Reviews: Buick Hellcat Tank,” Automobile February 2005, www.automobilemag. com, accessed 20 May 2010; Alfred P. Sloan with John McDonald, My Years with General Motors (Garden City, NY: Doubleday, 1964); Edwin Storm’s Free Car Brochures website at the Old Car Manual Project (storm.oldcarmanualproject. com); Robert Temple, “Transmissions and Drive Lines (Know Your Car Part Two),” Motor Trend Vol. 15, No. 1 (January 1963), pp. 54-59; “The Autocar road tests 1814: Buick Special,” The Autocar 31 March 1961: 494–497; “The New Buicks: Slicker, Smoother,” Popular Science Vol. 153, No. 6 (December 1948), pp. 106–107; “The New Buick: With Hydraulic Torque Converter and Two-speed Epicyclic Gear,” The Motor 21 January 1948, reprinted in Buick Performance Portfolio 1947-1962, pp. 6-9; Wayne Thoms, “Road Trial: Buick Special,” Motor Trend Vol. 12, No. 12 (December 1960), pp. 22–27; Robert M. Tuck and James J. Mooney, Jr., assignors to General Motors Corporation, “Transmission,” U.S. Patent No. 2,929,270, filed 7 March 1957, issued 22 March 1960; U.S. Department of the Army, Principles of Automotive Vehicles (Department of the Army Technical Manual TM 9-2700) (Washington, DC: U.S. Government Printing Office, November 1947); Jim Whipple, “Buick Special’s performance-plus economy,” Popular Mechanics Vol. 115, No. 3 (March 1961), pp. 122–125, 286–291; and “PM’s 1000-Mile Road Test of Buick’s New V-6,” Popular Mechanics Vol. 116, No. 4 (October 1961), pp. 108–111, 258–260; ‘woodbox’ and ‘Buickspec6231,’ “1963 Skylark Dynaflow trans help required,” Team Buick, 20 November 2011, www.teambuick. com/ forums/ showthread.php?20995-1963-Skylark-Dynaflow-trans-help-required/, accessed 21 February 2016; and Jim Wright, “A Wildcat from Buick,” Motor Trend Vol. 14, No. 8 (August 1962), reprinted in Buick Performance Portfolio 1947-1962, pp. 136-140, and “Chevrolet Impala SS 250 H.P. 340 H.P.,” Motor Trend Vol. 15, No. 3 (March 1963), reprinted in Impala & SS Muscle Portfolio 1958–1972, pp. 48–53.

Additional information on the Controlled Coupling Hydra-Matic came from August H. Borman, Jr.; Forrest R. Cheek; and Milton H. Scheiter, assignors to General Motors Corporation, “Controlled Coupling Automatic Transmissions,” U.S. Patent No. 3,048,055, filed 27 December 1954, issued 7 August 1962; Ray Brock, “Olds … ’59 Class Leader,” Hot Rod June 1959, reprinted in Oldsmobile Automobiles 1955–1963, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1989), pp. 44–48, 60; “Olds 88 for ’60,” Hot Rod January 1960, reprinted in ibid, pp. 51–55; and “Pontiac – 3000 Mile Road Test,” Hot Rod December 1958, reprinted in Pontiac Limited Edition: 1949-1960, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1999), pp. 74–79, 89; Arch Brown, “1957 Nash Ambassador: Twilight of the Dinosaurs,” Special Interest Autos #115 (January-February 1990), reprinted in The Hemmings Book of Nashes: driveReports from Special Interest Autos magazine, eds. Terry Ehrich and Richard A. Lentinello (Bennington, VT: Hemmings Motor News, 2002), pp. 110–117; “1959 Cadillac Eldorado Biarritz: Nothing Succeeds Like Excess,” Special Interest Autos #88 (August 1985), reprinted in Cadillac Automobiles 1949–1959, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1990), pp. 92–100; the Cadillac & LaSalle Club Modified Chapter website (www.modifiedcadillac.org); Cadillac Motor Car Division of General Motors Corporation, “Cadillac data book ’56,” September 1955; “Car Life Consumer Analysis: 1956 Cadillac,” Car Life Vol. 4, No. 5 (June 1956), reprinted in Cadillac Automobiles 1949-1959, pp. 52–53; “Car Life Consumer Analysis: 1956 Pontiac,” Car Life Vol. 4, No. 2 (March 1956), reprinted in Pontiac Limited Edition: 1949-1960, pp. 46–47; Floyd Clymer, “Owners Praise Cadillac’s Performance But Complain of Transmission Troubles,” Popular Mechanics Vol. 105, No. 4 (April 1956), pp. 105–108, 250–258; “Controlled Coupling Hydra-Matic Fundamentals,” Chilton’s Auto Repair Manual (Philadelphia, PA: Chilton Book Company, 1958), pp. 79-132; Jack R. Doidge and Victor C. Moore, assignors to General Motors Corporation, “Transmission,” U.S. Patent No. 2,947,199, filed 26 November 1957, issued 2 August 1960; Walter B. Herndon, assignor to General Motors Corporation, “Controlled Coupling Multistep Automatic Transmissions,” U.S. Patent No. 2,876,656, filed 23 November 1953, issued 10 March 1959; and “Variable Capacity Pressure System for Transmissions,” U.S. Patent No. 2,875,699, filed 19 July 1954, issued 3 March 1959; Bill Holland, “Bill Holland Tests … The Cadillac 60 Special,” Motorsport May 1956, reprinted in Cadillac Automobiles 1949-1959, pp. 54–56; “Hydra-Matic Dampens That Thump,” Popular Science Vol. 167, No. 5 (November 1955), pp. 119–121, 260; John F. Katz, “1956 Oldsmobile Super 88 Convertible,” Special Interest Autos #145 (January-February 1995), reprinted in The Hemmings Book of Oldsmobiles: driveReports from Hemmings Special Interest Autos magazine, ed. Terry Ehrich (Bennington, VT: Hemmings Motor News, 2001), pp. 65-74; and “1960 Pontiac Bonneville Vista,” Special Interest Autos #172 (July-August 1999), reprinted in The Hemmings Motor News Book of Pontiacs: driveReports from Hemmings Special Interest Autos magazine, ed. Terry Ehrich (Bennington, VT: Hemmings Motor News, 2001), p. 68-77; Oliver K. Kelley, assignor to General Motors Corporation, “Combination Fluid Turbo Clutch and Variable Speed Gearing,” U.S. Patent No. 2,176,138, applied 5 February 1937, issued 17 October 1939; “Fluid Flywheel Gearing Arrangement,” U.S. Patent No. 2,211,233, applied 10 April 1939, issued 13 August 1940; and “Transmission Drive,” U.S. Patent No. 2,377,696, filed 15 December 1941, issued 5 June 1945; Dale Kelly, “An Engineer Analyzes the 1957 Oldsmobile,” Popular Mechanics Vol. 108, No. 1 (July 1957), reprinted in Oldsmobile Automobiles 1955–1963, pp. 25–26; Al Kidd, “drivescription: ’56 Oldsmobile,” Motor Trend Vol. 7, No. 12 (December 1955) and “’56 Oldsmobile Road Test, “Motor Trend Vol. 8, No. 4 (April 1956), reprinted in ibid, pp. 12-13 and 16-19; Ed Mobley, “Controlled Coupling Hydramatic/Jetaway Automatic Rebuild,” Edscars, 2006, www.photopaige. com/ edscars/ 60caddy/ CaddyWebSitev2_files/ TrannyRebuild2.htm, accessed 29 May 2010; Victor C. Moore, assignor to General Motors Corporation, “Transmission,” U.S. Patent No. 2,919,607, filed 30 November 1956, issued 5 January 1960; “New Cars Described: 1956 Pontiacs Have Latest Transmission,” The Autocar 18 November 1955, reprinted in Pontiac Limited Edition: 1949-1960, p. 45; “1960 Pontiac Tempest,” Hot Rod May 1960, reprinted in Pontiac Limited Edition: 1949-1960, pp. 86–89; Oldsmobile Division, General Motors Corporation, “’58 Oldsmobile” [brochure, ca. November 1957]; “Oldsmobile” [1956 brochure, ca. October 1955]; and “Oldsmobile’s New Jetaway Hydra-Matic” [brochure], 1955; Pontiac Motor Division of General Motors Corporation, “Answers That Sell: 1964 New Product Facts” [dealer literature], 30 August 1963; “Facts About the New ’56 Pontiac: Star Chief, 870 and 860 series” [dealer literature], September 1955; “Introducing Your 1957 Pontiac” (Pontiac 1957 Owner’s Guide S-5701), January 1957; 1957 Hydra-Matic Manual (with 1956 Appendix) (Pontiac, MI: Pontiac Motor Division, General Motors Corporation, March 1957); and “Pontiac ’58” [brochure, ca. October 1957]; “Oldsmobile: not the rocket it used to be,” Motor Life March 1960, reprinted in Oldsmobile Automobiles 1955–1963, pp. 56–57; “Oldsmobile Road Test,” Motor Life February 1959, reprinted in ibid, pp. 42–43; “Power Is Oldsmobile’s Top Feature, Say Owners from Coast to Coast,” Popular Mechanics Vol. 108, No. 1 (July 1957), reprinted in ibid, pp. 24–26; “The 1956 Cadillac,” Motor Life December 1955, reprinted in Cadillac Automobiles 1949-1959, p. 49; William K. Toboldt and Larry Johnson, Goodheart-Willcox Automotive Encyclopedia (South Holland, IL: The Goodheart-Willcox Company, Inc., 1975); Johnny Tolan, “Johnny Tolan Tests the ’57 Oldsmobile,” Speed Age March 1957, reprinted in Oldsmobile Automobiles 1955–1963, pp. 20–23; United Motors Service Division, The Hydra-Matic Transmission 1946-1955: On-the-Car Adjustment Service Manual (Detroit, MI: United Motors Service Division of General Motors Corporation, 1956), and Hydra-Matic Controlled Coupling Transmission Service Manual (Bulletin A-3755) (Detroit, MI: United Motors Service Division of General Motors Corporation, 1 November 1957); U.S. War Department, Ordnance Maintenance: Hydra-Matic Transmission and Propeller Shafts for Light Tanks M5, M5A1, and 75-MM Howitzer Carriage (War Department Technical Manual TM 9-1727C (Washington, DC: U.S. Government Printing Office, 5 February 1943); Joe H. Wherry, “’58 Oldsmobile on trial,” Motor Trend Vol. 10, No. 3 (March 1958), reprinted in Oldsmobile Automobiles 1955–1963, pp. 30–35; and Otto Zipper, “Road Test: Two Pontiacs,” Motor Trend Vol. 9, No. 3 (March 1957), reprinted in Pontiac Limited Edition: 1949-1960, pp. 54–57, 59. John D. Kelly later helped us to sort out some technical points about the original single-coupling unit in emails to the author, 7 to 8 March 2017.

Additional information on the triple-turbine automatics came from Al Berger, “’59 Chevrolet Has Fins, Will Travel,” Speed Age December 1958, reprinted in Impala & SS Muscle Portfolio 1958–1972, pp. 12–15; Terry Boyce, “Paragon of Excess: 1958 Buick Limited,” Special Interest Autos #53 (September-October 1979), reprinted in The Hemmings Book of Buicks, pp. 65-71; Johnny Boyd, “Johnny Boyd Tests the ’57 Buick,” Speed Age June 1957, reprinted in Buick Performance Portfolio 1947-1962, pp. 68–71; Arch Brown, “1957 Chevrolet Bel Air: The Really Hot One,” Special Interest Autos #96 (November-December 1986), reprinted in The Hemmings Book of Postwar Chevrolets, pp. 54-69; “Buick Builds a Better One,” Hot Rod March 1959, reprinted in Buick Performance Portfolio 1947-1962, pp. 92–95, 104; “Buick 1960,” Motor Trend Vol. 11, No. 11 (November 1959), reprinted in ibid, pp. 96–97; Jim Carroll, “’59 Buick on Trial,” Motor Trend Vol. 10, No. 10 (October 1958), reprinted in ibid, pp. 87-91; Charles S. Chapman, Jr., and Kenneth W. Gage, assignors to General Motors Corporation, “Transmission,” U.S. Patent No. 2,912,876, filed 20 May 1957, issued 17 November 1959; Chevrolet Engineering Center, Engineering Product Information Department, 1957 Chevrolet Engineering Achievements: Passenger Car Features (Detroit, MI: October 1956); Chevrolet Motor Division of General Motors Corporation, “Chevrolet 1957” [brochure, ca. October 1956]; “Chevrolet 1958: It Goes Big…With Spectacular New Shape!” [brochure, ca. October 1957]; 1958-1960 Chevrolet Turboglide Transmission: Construction and Operation (Detroit, MI: Chevrolet Motor Division, General Motors Corporation, May 1960); Gilbert K. Hause, assignor to General Motors Corporation, “Transmission,” U.S. Patent No. 2,919,608, filed 2 August 1956, issued 5 January 1960; Vincent Douglas, “1961 Impala: Big-Block Chevy, Family Style,” Special Interest Autos #147 (May-June 1995), reprinted in The Hemmings Book of Postwar Chevrolets, pp. 78–85; Tim Howley, “1959 Buick Electra 225 Convertible: Flash and Fins,” Special Interest Autos #126 (November-December 1991), reprinted in The Hemmings Book of Buicks, pp. 72-77; and “SIA comparisonReport: ’58 vs. ’59 Chevrolet Impala: What a Difference a Year Makes!” Special Interest Autos #140 (March-April 1994), reprinted in The Hemmings Book of Postwar Chevrolets, pp. 70–77; Oliver K. Kelley, assignor to General Motors Corporation, “Hydraulic Torque Converter,” U.S. Patent No. 2,882,684, filed 17 July 1956, divided 31 July 1957, issued 21 April 1959; and “Transmission,” U.S. Patent No. 2,964,976, filed 13 January 1958, issued 20 December 1960; Oliver K. Kelley and Gilbert K. Hause, assignors to General Motors Corporation, “Triple Turbine Bus and Truck Transmissions,” U.S. Patent No. 3,021,727, filed 13 October 1958, issued 20 February 1962; Oliver K. Kelley, Gilbert K. Hause, and Frank A. Swindell, assignors to General Motors Corporation, “Reactor Blade Pitch Control of a Hydro-Dynamic Torque Converter,” filed 6 March 1957, issued 10 November 1959; Richard M. Langworth, “Something Ventured, Nothing Gained: The Story of the 1957-58 Buick,” Collectible Automobile Vol. 17, No. 5 (February 2001), pp. 8–21; Mike Mueller and Anthony Young, Classic Chevy Hot Ones: 1955–1957 2nd ed. (Ann Arbor, MI: Lowe & B. Hould Publishers, 2002); “1958 Chevrolet Impala Road Test,” Motor Life January 1958, reprinted in Impala & SS Muscle Portfolio 1958–1972, pp. 5-7; Tom Sidoti, “1959 Buick Triple Turbine Transmission,” 1959 Buick Electra 225 Convertible, 20 October 2009, 1fine59. com/?paged=2, accessed 17 November 2015; “Testing the 60’s: Chevrolet V-8: Plushness…with a Price,” Motor Life February 1960, reprinted in Impala & SS Muscle Portfolio 1958–1972, pp. 21-22; “The 1959 Buick,” Motor Life November 1958, reprinted in Buick Performance Portfolio 1947-1962, p. 80–83; Jim Whipple, “Car Life 1958 Consumer Analysis: Buick,” Car Life Vol. 6, No. 3 (April 1958), reprinted in ibid, pp. 72–75; Frank J. Winchell and Oliver K. Kelley, assignors to General Motors Corporation, “Transmission,” U.S. Patent No. 3,008,349, filed 25 February 1957, issued 14 November 1961; and Walt Woron, “Chevrolet ’57,” Motor Trend Vol. 8, No. 12 (December 1956), reprinted in Chevrolet 1955-1957, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1988), pp. 64-68.

Additional information on Roto Hydra-Matic came from “Autocar Road Test 1908: Vauxhall Cresta Hydra-Matic 2,651 c.c.,” Autocar 11 January 1963, pp. 58–62; Terry Bebbington, “EJ-EH Holden History and Information,” Australian Classic Car December 2003; August H. Borman, Jr.; Charles W. Cline; and Carl E. Shellman, assignors to General Motors Corporation, “Transmission,” U.S. Patent No. 3,132,535, filed 20 September 1960, issued 12 May 1964; “Car Life Road Test: Oldsmobile F-85,” Car Life Vol. 9, No. 4 (May 1961), reprinted in Oldsmobile Automobiles 1955-1963, pp. 66-70; “Car Life Road Test: Oldsmobile 98 Holiday Sports Sedan,” Car Life Vol. 10, No. 3 (April 1962), reprinted in ibid, pp. 74-78; “EJ Holden,” “EK Holden,” and “Holden History,” Unique Cars and Parts [Australia], n.d., www.uniquecarsandparts. com.au, accessed 12 November 2015; Ken Fermoyle, “Buick, Olds, Pontiac Go Compact,” Popular Science Vol. 177, No. 4 (October 1960), pp. 72–76, 244–246; General Motors Continental, “Kapitän / Kapitän L” [Dutch brochure, ca. 1961]; General Motors-Holden Ltd., “Holden: Australia’s Own Car” [EK Holden brochure, 1961]; Walter B. Herndon, “GM develops light-weight, compact, Hydra-Matic transmissions,” The SAE Journal Vol. 69, No. 3 (March 1961), pp. 46–48; Walter B. Herndon and Howard E. Olsen, assignors to General Motors Corporations, “Transmission,” U.S. Patent No. 3,141,354, filed 8 March 1962, issued 21 July 1964; “Hydra-Matic 61-05 Transmission, Parts I and II,” Automobile Engineer Vol. 50, No. 15 (December 1960), pp. 524–31, and Vol. 51, No. 1 (January 1961), pp. 2–8; J.L. Spoormaker N.V., “Opel” [Dutch brochure], 1961; Oliver K. Kelley, Stanley L. Buckay, and Paul J. King, assignors to General Motors Corporation, “Balanced Inertia Plural Step-Ratio Transmissions,” filed 29 April 1955, issued 6 March 1962; “Olds F-85: Another Rocket Hits the Road,” Popular Mechanics Vol. 114, No. 4 (October 1960), p. 100–102, 310; Oldsmobile Division, General Motors Corporation, “F-85 by Oldsmobile” [brochure], February 1961; “Oldsmobile for ’64: Where the Action Is!” [brochure], September 1963; “’61 Olds” [brochure], October 1960; “’62 Oldsmobile” [brochure], September 1961; “’63 Oldsmobile” [brochure], September 1962; and “’64 Oldsmobile: Models • Equipment • Prices” [dealer literature], February 1964; “Oldsmobile Dynamic 88 Celebrity Sedan,” Car Life Vol. 10, No. 7 (August 1962), reprinted in Oldsmobile Automobiles 1955-1963, pp. 84-87; “Oldsmobile F-85,” Car and Driver Vol. 6, No. 11 (May 1961), reprinted in ibid, pp. 71-73, 100; “Oldsmobile F-85,” Motor Trend Vol. 13, No. 2 (February 1961), reprinted in ibid, pp. 61-65; Oldsmobile Mail List Server Community, “Transmissions,” Olds FAQ, 1996–2000, www.442. com/oldsfaq/ oftrn.htm, last accessed 15 February 2016; Pontiac Motor Division of General Motors Corporation, “Answers That Sell: 1964 New Product Facts” [dealer literature], 30 August 1963; “1961 Pontiac” [brochure, ca. September 1960]; “Come see our ’63 Pontiacs” [brochure, ca. October 1962]; and “Wide-Track Pontiac ’62” [brochure, ca. October 1962]; “Transmissions,” Popular Mechanics Vol. 115, No. 1 (January 1961), pp. 157–158; and Jim Whipple, “PM Owners Report: Nimble Olds F-85 Pleases Owners; Mileage, Transmission Draw Fire,” Popular Mechanics Vol. 120, No. 1 (July 1963), pp. 76–79, 196–197.

Additional information on the Corvair Powerglide and Pontiac TempesTorque came from Bill Carroll, “Inside Pontiac’s Terrific Tempest!” Sports Cars Illustrated Vol. 6, No. 4 (October 1960)) and “Pontiac Tempest Road Research Report,” Sports Cars Illustrated Vol. 6, No. 9 (March 1961), both reprinted in Car and Driver on Pontiac 1961–1975, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1986), pp. 5-16; Chevrolet Motor Division of General Motors Corporation, “Corvair by Chevrolet: The Prestige Car in Its Class” [1960 brochure], 1959; “Corvair Automatic Transmission (Road & Track Road Test 235),” Road & Track Vol. 11, No. 6 (February 1960), reprinted in Corvair Performance Portfolio 1959-1969, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1998), pp. 22–23; Ken Fermoyle, “Pontiac Tempest: Radical New Compact,” Popular Science Vol. 177, No. 3 (September 1960), pp. 53–58; Wick Humble, “1961 Pontiac Tempest: But cars aren’t supposed to have curved driveshafts,” Special Interest Autos #48 (November-December 1978), reprinted in The Hemmings Motor News Book of Pontiacs, pp. 74–86; Oliver K. Kelley, Kenneth W. Gage, and Richard W. Craig, assignors to General Motors Corporation, “Transmission and Swinging Drive Axles Including Torque Converters,” U.S. Patent No. 3,170,534, filed 7 January 1959, issued 23 February 1965; Karl Ludvigsen, “SCI Analyzes Ed Cole’s CORVAIR,” Sports Cars Illustrated Vol. 5, No. 5 (November 1959), reprinted in Corvair Performance Portfolio 1959-1969, pp. 5–13, 17; Jan P. Norbye and Jim Dunne, Pontiac 1946-1978: The Classic Postwar Years (Osceola, WI: Motorbooks International Publishers & Wholesalers, 1979); Pontiac Motor Division of General Motors Corporation, “1962 Tempest by Pontiac” [brochure, ca. October 1961]; “’63 Pontiac Tempest” [brochure, ca. October 1962]; and “Tempest: Quality Newcomer from Pontiac!” [brochure, ca. November 1960]; and Wayne Thoms, “Tempest Le Mans,” Motor Trend Vol. 15, No. 2 (February 1963), pp. 54–59.

Other background information came from Robert Ackerson, “1950 Packard DeLuxe Eight: The Last of Packard’s Postwar Pachyderms,” Special Interest Autos #64 (July-August 1981), reprinted in The Hemmings Motor News Book of Packards: driveReports from Special Interest Autos magazine, eds. Terry Ehrich and Richard Lentinello (Bennington, VT: Hemmings Motor New, 2001), pp. 58–65; Allison Transmission’s History-Heritage page at www.allisontransmission. com, accessed 13 October 2015; Oscar H. Banker, “Change Speed Planetary Transmission,” United States Patent No. 2,077,387, applied 16 July 1934, renewed 22 March 1935, issued 20 April 1937; Oscar H. Banker, “Transmission Mechanism,” U.S. Patent No. 1,795,465, filed 26 November 1928, issued 10 March 1931; Oscar H. Banker, assignor to Continental Illinois Bank and Trust Company, “Transmission,” U.S. Patent No. 1,795,464, filed 21 October 1927, issued 10 March 1931; “Transmission,” U.S. Patent No. 2,003,963, filed 21 March 1930, issued 4 June 1935; “Automatic Transmission,” U.S. Patent No. 1,843,193, filed 9 April 1930, issued 2 February 1932; “Automatic Change Speed Transmission,” U.S. Patent No. 1,843,195, filed 12 February 1931, issued 2 February 1932; “Automatic Clutch,” U.S. Patent No. 1,851,146, filed 20 March 1930, issued 29 March 1932; “Automatic Change Speed Transmission,” U.S. Patent No. 1,943,293, filed 24 July 1931, issued 16 January 1934; Oscar H. Banker, assignor to New Products Corporation, “Variable Speed Transmission,” U.S. Patent No. 1,937,503, filed 3 September 1931, issued 5 December 1933; “Clutch Mechanism,” U.S. Patent No. 2,042,454, filed 19 March 1932, issued 2 June 1936; “Automatic Change Speed Transmission,” U.S. Patent No. 1,996,790, filed 3 November 1932, issued 9 April 1935; “Change Speed Transmission,” U.S. Patent No. 1,985,884, filed 14 December 1932, issued 1 January 1935; “Planetary Transmission Mechanism,” U.S. Patent No. 2,005,726, filed 29 June 1933, issued 25 June 1935; “Change Speed Transmission,” U.S. Patent No. 2,077,387, filed 16 July 1934, issued 20 April 1937; “Clutch Mechanism,” U.S. Patent No. 2,104,014, filed 16 July 1934, issued 4 January 1938; “Automatic Transmission,” U.S. Patent No. 2,199,095, filed 13 October 1934, issued 30 April 1940; “Change Speed Transmission,” U.S. Patent No. 2,140,502, filed 30 November 1934, issued 20 December 1938; “Automatic Transmission,” U.S. Patent No. 2,171,534, filed 29 May 1935, issued 5 September 1939; “Automatic Transmission,” U.S. Patent No. 2,262,747, filed 18 September 1936, issued 18 November 1941, reissued 18 May 1943; and “Automatic Transmission,” U.S. Patent No. 2,237,297, filed 15 September 1937, issued 8 April 1941; Oscar H. Banker (with Robert Hull), Dreams and Wars of an American Inventor: an immigrant’s romance (Bay Village, OH: Bob Hull Books & Features, 1982); the BH Transmission Services Ltd. website (bhtransmission. co.uk/overview.html, accessed 5 November 2015); “British and European Car Spotters Guide – 1948,” Unique Cars and Parts, uniquecarsandparts. com/ car_spotters_guide_europe_1948.htm, accessed 15 October 2015; Buick Motor Division of General Motors Corporation, “Buick 1969” [brochure 69-BA-01 3MM], September 1968; “Buick ’65” [brochure, ca. October 1964]; and “The Book of New Buicks: 1964 Edition” [brochure, ca. October 1963]; David Burgess-Wise, “A good idea at the time: The Black Prince,” The Telegraph 13 October 2001, www.telegraph. co.uk, accessed 15 October 2015; “Cadillac,” Motor Trend Yearbook 1966, reprinted in Cadillac Automobiles 1960–1969, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1992), p. 78; Cadillac Motor Car Division, General Motors Corporation, “1966 Cadillac: New Elegance…New Excellence…New Excitement” [brochure], 1966; and “1968 Cadillac” [brochure], 1968; “Cadillac Series 60,” Car Life Vol. 11, No. 10 (November 1963), reprinted in Cadillac Automobiles 1960–1969, pp. 48–49; “Car Life Road Test: Buick LeSabre 400,” Car Life Vol. 12, No. 12 (January 1965), reprinted in Buick Muscle Portfolio 1963-1973, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2001), pp. 33–37; “Car Life Road Test: Buick Skylark & Gran Sport,” Car Life Vol. 13, No. 3 (April 1965), pp. 45–50; “Car Life Road Test: Cadillac Sedan de Ville,” Car Life Vol. 12, No. 6 (July 1964), reprinted in Cadillac Automobiles 1960–1969, pp. 56–59; “Car Life Road Test: California GS,” Car Life Vol. 15, No. 5 (June 1967), reprinted in Buick Muscle Portfolio 1963-1973, pp. 70–74; “Car Life Road Test: GS 400,” Car Life Vol. 14, No. 12 (January 1967), reprinted in ibid, pp. 60–65; “Car Life Road Test: 1964 Buick Electra 225 Hardtop Coupe,” Car Life Vol. 12, No. 1 (February 1964), reprinted in Buick Muscle Portfolio 1963-1973, pp. 17-21; “Car Life Road Test: 1964 Oldsmobile Cutlass Holiday,” Car Life Vol. 11, No. 11 (December 1963), reprinted in Oldsmobile Muscle Portfolio 1964–1971, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1999), pp. 11–17; “Car Life Road Test: Oldsmobile Delta 88,” Car Life Vol. 13, No. 3 (April 1965), reprinted in ibid, pp. 33–37; Chevrolet Motor Division of General Motors Corporation, “Chevrolet Camaro” [brochure D-78776 R-1], 1969; “Chevy’s New Little Car Is Open for Business” [brochure 1102], ca. September 1970; “Discover all the facts and features about the beautiful full-size Chevrolet ’66” [brochure], 1965; “1940 Chevrolet: Special Deluxe, Master Deluxe, Master 85,” [brochure, ca. September 1939]; “1954 Chevrolet Advance-Design Trucks: For Loads of Value: [brochure 1,000 M], October 1953; “1971 Nova Coupe/Sedan/SS” [brochure 1144 R-1], January 1971; “’72 Nova. How to see less of your mechanic and more of America.” [brochure 1618], September 1971; “’74 Nova: Building a better way to see the U.S.A.” [brochure 2676], September 1973; “’74 Vega” [brochure 2677-Rev], January 1974; and “The Little Car That Does Everything Well” [Vega brochure 1619], September 1971; Allan Coats, “Rotary Power Transmission Mechanism,” U.S. Patent No. 1,760,480, filed 4 December 1925, issued 27 May 1930; and “Rotary Mechanism for Transmission of Power,” U.S. Patent No. 1,760,397, filed 18 November 1927, issued 27 May 1930; John Etheridge, “It’s White Tie & Tails for Chevy Caprice ‘396,’” Motor Trend Vol. 17, No. 6 (June 1965), pp. 48–53; Hermann Föttinger, “Flüssigkeitsgetriebe mit einem oder mehreren treibenden und einem oder mehreren getriebenen Turbinenräder zur Arbeitsübertragung zwischen benachbarten Wellen,” DRP Nr. 221422, filed 24 June 1905, issued 25 April 1910; Hermann Föttinger, assignor to Stettiner Maschinenbau AG ‘Vulcan,’ “Hydraulic Device for Transmitting Power,” U.S. Patent No. 1,199,359, filed 19 June 1906, issued 26 September 1916; “Transmission Device,” U.S. Patent No. 1,199,360, filed 26 January 1910, issued 26 September 1916; and “Transmission Device,” U.S. Patent No. 1,199,361, filed 26 January 1910, issued 26 September 1916; General Motors Corporation, “GM Powertrain: Past, Present, Future,” www.gm. com/experience/ technology/ gmpowertrain/ about/powertrain_history.jsp [now www.gmpowertrain. com], accessed 28 May 2010; “Golden Anniversary Packard Models,” The Motor 6 July 1949, reprinted in Packard Gold Portfolio 1946-1958, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1988), pp. 19–21; Tony Hogg, “Audi 5000 Turbo,” Road & Track Vol. 31, No. 9 (May 1980): pp. 62–64; Ari Holopainen, “Planetary Gears,” LUGNET News, 2005, www.lugnet. com/~3813/epicyclic, accessed 9 June 2017; Roger Huntington, “The Great Transmission Controversy: Coupling vs. Converter,” Car Life Vol. 10, No. 2 (March 1963), pp. 18–21, and “Turnpike Cruiser: Oldsmobile Designs a Long-Legged, Strong-Willed Gas Miser,” Car Life Vol. 14, No. 3 (April 1967), reprinted in Cutlass and 4-4-2 Muscle Portfolio 1964–1974, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1998), pp. 34–39; “Invicta Black,” Motorstown, n.d., www.motorstown. com/news/ 1091-invicta-black.html, accessed 15 October 2015; “Invicta Black Prince,” A to Z of Cars, Classic & Sports Car, 29 March 2011, www.classicandsportscar. com, accessed 15 October 2015; Invicta Car Development Co., “Invicta” [brochure, 1947]; Robert W. Irwin, “GM’s New 3-Speed Automatic Transmission,” Motor Trend Vol. 20, No. 9 (September 1968), pp. 44–45; Achim Leutz’s Hermann Föttinger website, hermann-foettinger.de, last updated 2014, accessed 24 September 2015; Patrick Lindemann, Markus Steinberger, Thorsten Krause, iTC, “Innovative Solutions for Torque Converters Pave the Way into the Future,” Schaeffler Symposium 2014 (Schweinfurt, Germany: Schaeffler Technologies AG & Co. KG), pp. 280–301; “Lost Marques: Invicta,” Unique Cars and Parts, www.uniquecarsandparts. com.au/ lost_marques_invicta.php, accessed 15 October 2015; Bob McVay, “Road Testing the Oldsmobile Jetstar 88,” Motor Trend Vol. 16, No. 4 (April 1964), reprinted in Oldsmobile Muscle Portfolio 1964–1971, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1999), pp. 5–10; Donald E. Meyer, “A Brief Outline of the First Century of GMC Truck History,” Generations of GM, GM Heritage Center, 8 March–14 April 2008, history.gmheritagecenter. com/ wiki/ index.php/ A_Brief_Outline_of_the_ First_Century_of_GMC_Truck_History, accessed 8 October 2015; Ralph Nader, Unsafe at Any Speed: The Designed-in Dangers of the American Automobile (New York: Grossman Publishers, 1965); Paul Niedermeyer, “Curbside Classic: GMC TDH-5105 Old Look Transit Bus – GM’s Greatest Hit #9, Despite Being the Agent of a GM Deadly Sin,” Curbside Classic, 3 April 2012, www.curbsideclassic. com/ curbside-classics-american/ curbside-classic-gmc-tdh-5105- old-look-transit-bus-gms-greatest-hit-9- despite-being-the-agent-of-a-gm-deadly-sin/, accessed 8 October 2015; Eric Nielssen, “Six Luxury Cars: a view from the Automotive Engineering Side,” Car and Driver Vol. 11, No. 1 (July 1965), 26–31, 62–65, 75; Oldsmobile Motor Division, General Motors Corporation, “1969 Oldsmobile: Salesmen’s Prices/Equipment, Colors and Trim/Specifications” [dealer literature] October 1968; “1970 Olds Escape Machine power teams” [brochure], 1970; and “The 1970 Escape Machines: Oldsmobile” [brochure], October 1969; Pontiac Motor Division of General Motors, “A device for shrinking time and distance: Pontiac GTO” [ad insert], Motor Trend Vol. 16, No. 4 (April 1964), nn; “Low-priced-car buyers rejoice! You’ve got a new choice. 1964 Wide-Track Pontiac Tempest.” [brochure, ca. October 1963]; “Nineteen Sixty Five Pontiac” [brochure, ca. October 1964]; “1972 Pontiac” [brochure DM 26627], August 1971; “Pontiac 1973” [brochure], August 1972; “Pontiac ’69” [brochure], October 1968; “Pontiac’s 70’s” [brochure DM 27229], September 1969; “Pure Pontiac” [brochure DM 29103], August 1970; Arthur Pound, The Turning Wheel: The Story of General Motors Through Twenty-Five Years 1908–1933 (Garden City, NY: Doubleday, Doran & Co., Inc., 1934); “Q&A: dangling definitions,” Motor Trend Vol. 20, No. 7 (July 1968), p. 102; Carlton R. Radcliffe, “Hydraulic Power Transmitting Apparatus,” U.S. Patent No. 1,576,996, filed 3 August 1920, issued 16 March 1926, and “Hydraulic Power Transmitting Apparatus for Motor Vehicles,” U.S. Patent No. 1,667,565, filed 24 April 1917, issued 24 April 1928; Pol Ravigneaux, “Speed Changing Device,” U.S. Patent No. 2,220,174, filed 22 August 1936, issued 5 November 1940; “Speed Changing Device,” U.S. Patent No. 2,194,954, filed 10 October 1937, issued 26 March 1940; “Gear Box With Free Wheeling Gear,” U.S. Patent No. 2,195,783, filed 29 December 1937, issued 2 April 1940; “Variable Speed Gear,” U.S. Patent No. 2,239,973, filed 7 July 1938, issued 29 April 1941; “Epicyclic Change-Speed Gear,” U.S. Patent No. 2,631,476, filed 22 July 1950, issued 17 March 1953; and “Epicyclic Change-Speed Gear,” U.S. Patent No. 2,761,333, filed 24 March 1952, issued 4 September 1956; Bill Sanders, “Now You Can Have It Too: Econoperforleration* (*Economy, Performance, Acceleration): Oldsmobile Has Added It for 1968,” Motor Trend Vol. 20, No. 7 (July 1968), pp. 94–97; Steve Simpson, “Corvair Among Coconuts,” Modern Motor September 1961, reprinted in Corvair Performance Portfolio 1959-1969, pp. 36–38, 48; R.P. Stevenson, “British Cars – Mechanical Marvels,” Popular Science Vol. 150, No. 6 (June 1947), pp. 158–162; Summit Racing, “Torque Converter Selection – Summit Racing Quick Flicks,” YouTube, 6 April 2012, https://www.youtu.be/j5JFMs8gdbs, accessed 23 September 2014; “The Hydraulic Torque Converter,” Rail Motor Society, n.d., www.railmotorsociety. org.au/ rm_trans_htc_page.htm, accessed 13 October 2015; “The Motor Road Test No. 16/56 (Continental): The Packard Clipper,” The Motor 27 June 1956, reprinted in Packard Gold Portfolio 1946-1958, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1988), pp. 142–145; Mark Theobald, “Yellow Coach,” Coachbuilt, 2004, www.coachbuilt. com, accessed 8 October 2015; Vincent Tocco, Jr., “Fluid Drive History,” American Blower, n.d., americanblowercorp. com, accessed 15 May 2010; Hans Tore Tangerud’s Autoblog website (www.lov2xlr8.no); U.S. War Department, Ordnance Maintenance: Ordnance Engine Model 975-C4 (Continental) (War Department Technical Manual 9-1725) (Washington, DC: U.S. Government Printing Office, 27 January 1944), and Ordinance Maintenance: Ford Tank Engines (Models GAA, GAF, and GAN) (War Department Technical Manual TM 9-1731B) (Washington, DC: U.S. Government Printing Office, June 1945); Vulcan Werke Hamburg, Stettiner Maschinenbau Actiengesellschaft, “Flüssigkeitsgetriebe zur Arbeitsübertragung zwischen benachbarten Wellen mittels treibender und getriebener Turbinenräder” DRP Nr. 238804, filed 24 June 1905, issued 30 September 1911; Ron Wakefield, “1970 Camaro & Firebird: Chevrolet & Pontiac versions of a new American GT, plus a facelifted Corvette for 1970,” Road & Track Vol. 21, No. 7 (March 1970), reprinted in Firebird and Trans-Am Muscle Portfolio 1967–1972, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1998), pp. 92–95; Alan Wenbourne, “Ravigneaux Planetary Transmission,” South East London Meccano Club, 2006, www.selmec. org.uk/ article_0001_ ravigneaux_planetary_transmission.aspx, accessed 11 October 2015; “Wilson, Charles E.,” Generations of GM History, GM Heritage Center, n.d., history.gmheritagecenter. com/ wiki/ index.php/ Wilson,_Charles_E., accessed 8 November 2015; and Frank J. Winchell, Jerry R. Mrlik, John E. Mahoney, Jack W. Qualman, Thomas R. Zimmer, and August H. Borman, assignors to General Motors Corporation, “Transmission and Control System,” U.S. Patent No. 3,321,056, filed 12 December 1963, issued 23 May 1967.

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Our inflation estimates came from the U.S. Bureau of Labor Statistics Inflation Calculator at data.bls.gov/cgi-bin/cpicalc.pl. Please note that inflation estimates are provided solely for readers’ general information; this is an automotive history, not a treatise on the historical value of money, and nothing in this article should be taken as financial advice of any kind!

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