8L90 & 8L45 Transmissions Explained

• All 8L transmissions are based on the same globally patented gearset concept as the ZF 8HP from 2008. While fully retaining the same gearset logic, they differ only in the patented arrangement of the components, with gearsets 1 and 3 swapped.
• The 8L 90 is the first 8-speed automatic transmission built by General Motors. It debuts in 2014 and is designed for use in longitudinal engine applications, either attached to the front-located engine with a standard bell housing or mounted in the rear of the car adjacent to the differential (as in the Corvette). It features a hydraulic (Hydramatic) design.
• The 8L45 is the smaller variant and debuted in 2015 in the 2016 Cadillac CT6. It is designed for use in longitudinal engine applications attached to the front-located engine with a standard bell housing. It is a hydraulic (Hydramatic) design sharing much with the 8L 90 transmission. Estimated weight savings over the heavier duty 8L 90 is 33 lb (15 kg).
• The ZF 8HP has become the new benchmark for automatic transmissions.