I grew up around the first independent shop in Nashville, Tennessee to work on automatic transmissions. In the late 1940's, my father opened a general automotive shop, after his tour in the USAF as a B-17 pilot. He specialized in precision tune-up, carburetor work, (Carter factory service center), and automatic transmissions.
The Powerglide was introduced in the 1951 Chevy passenger car, along with the early 235 babbit-pounder engine. Chevy and GMC trucks got the 4-speed Hydramatic, a beefed-up version of the Olds/Pontiac/Cadillac transmission. By the early 60's, (1962, I think) a few Chevy pickups were equipped with the aluminum-case powerglide, which was a major redesign of the transmission. It only lasted about 3 years or so, replaced by the Turbo 350.
The first automatic-equipped car to arrive in Nashville was a 1951 BelAir 2-door hardtop, also the first of its kind, accompanied by a huge advertising campaign which was launched to introduce its roll-out, with all the hoopla that a new model received back then. The night before it was to hit the showroom for the first time, an bunch of salesman were out raising hell in the new demonstrator, impressed with its performance, and generally having a good time. It wouldn't surprise me if more than a few drinks might have been consumed along the way. As they were running along at about 80 MPH or so, somebody asked "What happens if you put it in reverse?" Somebody else spoke up- - -"It won't hurt a Studebaker!" (The Stude automatic had a reverse lockout above 5 MPH, something Chevy engineers didn't think about) The driver said, "Well, a Chevy is better than any old Studebaker"- - - -accompanied by a yank on the shifter! Reverse promptly engaged, splitting the transmission housing wide open! I think it trashed the rear end and the driveshaft along the way. Tow truck time! The nearest replacement transmission was somewwhere in Michigan, so the car sat in the showroom for about two weeks, with stacks of newspaper under it, soaking up the drips from the broken case.
Early Powerglides had a cast iron case, and they weren't famous for performance or durability. They did have a torque converter which multiplied engine torque for breakaway from a stop, something the 4-speed Hydramatic didn't have. It used a fluid coupling instead, which got almost a 100% speed lockup, but did not increase torque. A torque converter almost doubles engine torque just before the car starts to move, but it can only achieve a 90% speed lockup. Some of the early converters like in the 1949 Studebaker "Automatic" and the 55 Packard Ultramatic incorporated a lockup clutch in the converter to eliminate this slippage at highway speed, something that came back into production with the 700R4 and a lot of other supposedly "modern" automatics. The Powerglide was a 2-speed, "Too low and too high" was the usual comment about it. The Chrysler Powerflite was also a 2-speed.
Ford used a 3-speed "Fordomatic" that started out in 2nd. gear in the early models and made an automatic 2-3 shift. It had to be shifted to Low range to get 1st. gear engaged. By about 1958 or so, they changed the shift pattern and added a selector position to choose between a 1st. or 2nd. gear start in Drive. This trans got renamed the "Cruise-O-Matic".
Now, Grasshopper, anything else you'd like to know from the oldtimer?
Jerry
