4T60,440-T4

A 4-speed transaxle which replaced the 125, was created for the 1985–1986 GM C platform (FWD)/GM H platform (FWD) cars, the Turbo-Hydramatic 440-T4. Virtually no internal parts were shared with the 125, and overdrive was achieved by departing radically from the standard single Simpson compound planetary gearset's common sungear layout. This transaxle was first used in GM's 1985 Buick Park Avenue, Oldsmobile 98, and Cadillac Deville. In 1986, after switching to FWD, the Buick LeSabre, Oldsmobile Delta 88, and later, the Pontiac Bonneville also used this transaxle. The 440-T4 was later renamed the 4T60 under GM's new transmission naming convention. A heavy-duty version of the 4T60 called the 4T60-HD was used in the 1989-1990 Pontiac Grand Prix with the turbocharged engine. GM started adding electronic controls to the 4T60 in 1990 with the Cadillac Allante carline's unique F7, and after 1991 with the corporate 4T60-E.