As you probably all know, I’ve been working for months on an extensive revamp of the second part of my 2010 article on GM’s early automatics, covering Dynaflow, Powerglide, their successors (including Twin Turbine Dynaflow, Turboglide, and Dual-Path Turbine Drive), and the later generations of Hydra-Matic. That revamp is now done.
The article has been almost completely rewritten, adding a lot of new information (more than doubling its length in the process) and incorporating a lot of corrections. Unlike the previous version, I’ve made a concerted effort to explain the mechanics of each of the 14 transmissions discussed.
This is the newly revised piece, covering Dynaflow, the early Powerglide, Controlled Coupling Hydra-Matic, Roto Hydra-Matic, Turboglide, and others. If you somehow missed the revamped Part 1, this is the history of the first-generation Hydra-Matic.