I first heard about the Torqueflite gearbox being used in the Jensen FF and other European cars that used large Chrysler Hemis for power. The gearbox was suitably mated to the Hemi because both came from Chrysler.
The first Torqueflite was released in 1956 as a 3-speed auto replacing the Powerflite which was a 2-speed box. Variants of the torqueflite can be found on Jeep and other Chrysler brands today, nearly 60 years later!
Early models had push button selectors in the dashboard instead of column mount or gear lever action. A “Park” lever was added from 1960 that put the box in Neutral, locked the shaft and buttons. Chrysler switched to the column shift to standardise their boxes with GM and Ford as the PRND21 sequence in the gearbox was defined by the Society of American Engineers to stop drivers selecting the wrong gear when driving an unfamiliar car.
The Torqueflite used the Simpson Gearset which consisted of two identical planetary gearsets linked together with a torque converter. The design was such that most of the gear components were identical thus reducing manufacturing costs as well as being very smooth to use. They started out with three forward ratios and one reverse gear ratio inside a cast iron shell, however in the 60s the iron was replaced with lighter aluminium.
During the 70s with the rise of more compact front-drive cars, Chrysler redesigned the gearbox to fit their smaller Chrysler, Plymouth and Dodge cars making it an integral part of the transaxle combined with a 2.2 or 2.5 litre engine. With badge engineering it also made its way into some Mitsubishi models!
Howard Simpson who had been an apprentice at Cadillac had spent most of his life designing planetary gears, initially for the Ford Tractor Company and then the Ford Motor Company. It was after he had resigned due to ill health that he designed his 3-speed gearset that was licenced to Chrysler – Ford had originally rejected it!
Chrysler subsequently started to sell the gearbox with or without engines to a wide variety of American and European manufacturers such as Jensen, Aston Martin Lagonda, Maserati (on the Quattroporte Series 3), Bristol, Monteverdi and Facel Vega, and AMC used it on their commercial and Jeep ranges (as TorqueCommand) before they were acquired by Chrysler. The gearbox, or its descendants are still being built and used on Chrysler models today. During the 90s they were called by model numbers rather than the name Torqueflite, however in 2014 the name came back – a nod to the heritage of the design. If you drive a Chrysler, Jeep or Dodge and it’s an auto, chances are it’s a Torqueflite!
The boxes have increased in size from 3 to now 8 speeds but the concept is still being used – both Ford and General Motors ended up buying a licence to build similar style gearboxes with the Simpson Gearset (the Ford Cruise-a-matic and GM Turbo-hydramatic) to compete with Chrysler. Even Mercedes-Benz licenced the gears for their own automatic transmissions.