Although the Hydra-Matic transmission was first used by Oldsmobile and Cadillac, the final user was not a GM division, but Rolls-Royce, which used its own license-built versions of this highly successful GM transmission from 1953 to 1978. This included an unusual, short-lived variation for the early Rolls-Royce Silver Shadow and Bentley T-Series — the last iteration of the original Hydra-Matic transmission. In this installment of Ate Up With Motor, we take a look at the upper-crust British career of this venerable American automatic transmission.
Continue Reading Don’t Call It Hydra-Matic: The Rolls-Royce and Bentley Automatic Gearbox
Category: Technology and Terminology
Explanations of various automotive terms and the technology under the hood.
Secrets of the Simpson Gearset
If you’re familiar with transmissions like the Chrysler TorqueFlite and GM Turbo Hydra-Matic (among others), you may have heard of the “Simpson gearset.” In this installment of Ate Up With Motor, we look at the origins and function of the Simpson gearset and briefly introduce you to its inventor, the late Howard W. Simpson.
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Giving Slip the Slip: Lockup Torque Converters and Split Torque Automatic Transmissions
Fluid clutches — fluid couplings and torque converters — have many advantages for automotive transmissions, but with those benefits comes a cost: fuel-wasting hydraulic slippage even at cruising speed. Since the 1940s, automakers have come up with a variety of strategies for reducing or eliminating that slip, including series parallel “split torque” transmissions and different types of converter lockup clutches. In this installment of Ate Up With Motor, we take a look at how GM, Ford, Chrysler, Packard, and Studebaker have approached this slippery problem from 1949 through the late eighties.
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The MacPherson Strut
Although frequently misunderstood and often misspelled, MacPherson struts are one of the most common suspension systems used on modern cars, found on everything from the Proton Savvy to the most formidable Porsche 911 Turbo. In this newly revised and updated installment of Ate Up With Motor, we’ll take a look at the origins and workings of the MacPherson strut, including modern variations like the Toyota Super Strut, GM HiPer Strut, and Ford RevoKnuckle.
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Dynaflow, Turboglide, Roto Hydra-Matic, and Other Early GM Automatics
The Hydra-Matic, GM’s first fully automatic transmission, was a great success, inspiring a host of rivals — including some within General Motors itself. In this installment of Ate Up With Motor, we look at the origins of Dynaflow and Powerglide, the ambitious but ill-fated Turboglide and Flight Pitch Dynaflow (a.k.a. Triple Turbine), the later Controlled Coupling Hydra-Matic and Roto Hydra-Matic, and more.
AUTHOR’S NOTE: This article, originally written in 2010, has been extensively revised and expanded for 2016.

Continue Reading Dynaflow, Turboglide, Roto Hydra-Matic, and Other Early GM Automatics
Hydra-Matic History: GM’s First Automatic Transmission
GM’s original Hydra-Matic transmission was one of the most important innovations in the history of the automobile. It wasn’t the first automatic transmission, but it was the first one that really worked and its resounding commercial success paved the for every subsequent auto-shifter. This week, we take a look at the origins of the Hydra-Matic and its originator, Earl Thompson, who also developed the first Synchro-Mesh gearbox back in the 1920s.

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A Weighty Issue: Shipping Weight and Curb Weight
A car’s weight has a dramatic effect on its performance, ride, handling, and fuel economy. Figuring out how much a car weighs should be simple, but the weights listed in brochures, road tests, and other sources can be contradictory and confusing. A vehicle’s specifications may list shipping weight, manufacturer’s curb weight, and gross vehicle weight ratings, all of which are quite different. To sort out this confusion, let’s look at what each of these terms means.
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From Pillar to Post: More Automotive Definitions
Periodically, we feel it’s worth taking the time to define some of the terms we throw around with which some readers may not be familiar. This week, we examine some of the terminology of automotive design.
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Super-iority: Defining the Supercar and Muscle Car
One of the minor but contentious arguments among automotive enthusiasts and historians is the question of exactly what constitutes a muscle car. Since we’ll be talking about several cars of this breed in the coming weeks, we thought we’d give you our take on this issue.
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The German Way: DIN Horsepower Ratings
Since we’ve been talking more about European cars this year, we have been making frequent references to “DIN” power ratings. We wanted to be sure everybody is clear on what that means.
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Hotchkiss Drive
Another term we have thrown around a lot that bears some explanation is Hotchkiss drive. This is a suspension layout very common on front-engine/rear-drive cars and trucks from the 1920s until the late 1970s and still used on many pick-up trucks and SUVs. In this installment of Ate Up With Motor, we’ll look at in more detail.
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Definitions: Homologation
In some of our past and upcoming articles, we’ve been throwing around the word homologation, and it occurs that we should pause to explain what it means.
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