4L40E Overhaul Kit Transmission parts, repair guidelines, problems, manuals

Transmission general data

Number of gears Transmission Type Drive Torque (Nm) ATF (full capacity) L ATF (change) L ATF type
4 AT RWD 360 9 5,5-6 Dexron VI
Part type (1) Expand

Technical issues and repair guidelines

The repair of this transmission mainly lies in the replacement of filter, gaskets and seals (preventing oil leakage), and replacement of burnt friction elements. All parts are interchangeable with 5L40E and 5L50E. Frictions are one-sided as in the popular DP0 transmission. The pack (Direct Clutch; 2nd Coast) burns twice as frequently as other clutch packs.Generally, this gearbox is considered to be reliable and almost “invincible”, when avoiding heavy ATF contamination by friction dust and the abradant which wears out not only friction nodes, but also the valve body.


This issue (oil contamination) often results in self-regulating pump becoming “unregulated”, also remaining in the mode of ultimate capacity. It leads to the rapid gear-shifting as well as to increased pressure in packages resulting in pistons damage. Issues with pistons is a typical soft spot for the 5-speed 5L40E and 5L50E (BMW Х5). The rubber-covered piston (forward) most commonly gets out of order because of its design peculiarities.It is usually recommended to take care about the ATF quality for this transmission.