5L40E Identification Chart
Like all GM Transmissions the trans code can be broken down to explain the details of the transmission.
The 5L40E is available in both Rear Wheel Drive and All Wheel Drive Configuration
Rear Wheel Drive Code: “M82”
All Wheel Drive Code: “MX5”
According to General Motors the 5L40E has an Engine Torque Rating of 250 ft·lbf or 340 N·m and 1814 kg GVWR
There is also a 5L50-E version designed for an Engine Torque Rating of 311 ft·lbf or 422 N·m and 2268 kg GVWR this was available in selected vehicles in the United States.
BMW X5 and Land Rover Discovery’s with the 5L40E transmission are known for failing due to over working the transmission. As they are classed as a sealed Transmission the oil often goes off like milk left in the sun and causes the internals to fail. Transmission Rebuilders recommend servicing these transmissions every 20,000kms or 12 Months which every accrues first.
One of the main problems found in all 5L40E Transmissions is the lockup clutch plate in the Torque Converter. The plate lining falls off and causes a metal on metal application filling the gearbox with metal. The lockup clutch material also then blocks the filter causing a no drive or reverse problem.
Recommended Oil is Dexron 111 however there are better oils available now.
Valvoline Dexron 6
Valvoline Maxlife (Synthetic)
Castrol Transmax (Full Synthetic)