GM 5L40-E and 5L50 are 5-speed automatic gearboxes with a manual control function. They have been produced since 1999. They are installed on a number of cars produced by General Motors. In particular, cars of such makes as Cadillac, Pontiac, Holden, Chevrolet, Saturn, Opel, and Land Rover are equipped with them. They are also found on BMW models under different gearbox codes.
How the GM 5L40-E and 5L50 work
GM 5L40-E and 5L50 gearboxes are based on a classic automatic transmission with a hydraulic torque converter and planetary gear sets. Thanks to special software they feature several operating modes, ensuring optimal settings for different driving conditions. Manual mode can be activated by moving the gear lever into the corresponding position, marked “M” for instance, and sliding the lever to “+” or “-” to shift gears up or down.
Technical characteristics of GM 5L40-E and 5L50 transmissions
| Gearbox code | Max engine capacity, L | Max engine torque, N·m | Car layout | Production start | Model applications |
| 5L40E (A5S360R) | 3.6 | 360 | RWD, AWD | 1999 | Cadillac CTS; BMW X5 E53; Pontiac Solstice; BMW E39; Cadillac STS; Cadillac SRX; Pontiac G8; BMW E46; BMW X5 E83; BMW Z3 E36 |
| 5L50E (A5S390R) | 4.6 | 450 | RWD, AWD | 2000 | Cadillac CTS; Cadillac SRX; BMW X5 E53; Cadillac XLR |
Common malfunctions of GM 5L40-E and 5L50 transmissions
- The oil pump is sensitive to high RPMs and tends to jam.
- The oil becomes contaminated with wear products of the torque converter lockup.
- Solenoids and hydraulic unit channels get clogged if the transmission fluid isn’t replaced on time.
- Oil starvation causes jerky gear shifting.
- Friction couplings get overheated and destroyed due to reduction of lubricant pressure.
- Moulded rubber pistons get burned due to overheating.
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