GM 8L90 tagged posts

Last time I showed you some interesting facts about the ZF 9HP transmission. Today I am going to talk about the latest GM 8L90 8-speed automatic transmission, which will be used on the 2015 Corvette.

Please do not be confused with the Cadillac CTS 3.6 V6 trim’s 8-speed transmission, that one is not the 8L90. Instead GM sourced it from Aisin and it is a completely different design.

First I would like to show you the structure diagram of the 8L90. The drawing is from the patent GM filed with the US Patent and Trademark Office several years ago. As expected in a patent document, the drawing looks terribly complicated...

All Corvette models (base and Z06) customers will have the option to choose a manual transmission or a 8 speed transmission. This GM developed 8AT (code name: 8L90) is different than the 8AT that is currently used in the Cadillac CTS 3.6 (which is sourced from Aisin).

The 8L90 transmission used in Corvette has different packaging requirements than other traditional 8AT units. Unlike other rear wheel drive cars, the Corvette’s transmission is installed in the rear side of the car, after the occupant cabin, which is suitable to optimize the front/rear weight distribution of the sports car...