BMW transmissions are known for being very well built, requiring minimal maintenance for optimal performance. In recent years, BMW began using “lifetime” transmission fluid, which is supposed to be good for 100,000 miles– or the expected life of the transmission. This has reduced required transmission maintenance in late model BMWs. However, older models still require regular transmission service, and even newer models are not immune to transmission issues that require service. Even “lifetime” fluid wears down and can start to negatively influence performance starting around 80,000 miles.
A vehicle’s transmission is a complex assembly that takes power generated by the engine and transfers it to the
wheels. Higher and lower gears transfer that power differently, for more low-end torque or higher speed. Over time, routine use causes small particles of the transmission’s metal to wear off and integrate into the transmission fluid. Clean transmission fluid allows smooth shifting and overall transmission operation.
While the shifting action itself, and the role transmission fluid plays, differs between automatic and manual transmissions, the impact of dirty transmission fluid is the same: poor performance, and increased wear on the mechanical parts, contributing to earlier transmission failure.
We at Boston Motor Werks emphatically recommend regular transmission service at every Inspection 2 service appointment (no later than every 60,000 miles), or at any sign of transmission grinding, slippage, or fluid leak. The reasoning is simple: fluid is cheaper than metal. Replacing your transmission fluid, even “lifetime” fluid, is cheaper than replacing your transmission (or parts thereof). Proactive maintenance will keep your BMW’s transmission performing at its best, and protect against unexpected failure.
Routine transmission service involves
- Draining the current transmission fluid.
- (Automatic only) Install new pan gasket and filter (if replaceable).
- Add the proper type and quantity of oil/fluid for your transmission.
- Check for leaks.
- Test drive the vehicle.