DIY: Differential Fluid Change

DIY: Differential Fluid Change

The rear differential should have its fluid changed every 60,000 miles. BMW called it “lifetime fill” but this is not recommended.

Parts Needed

• 1 liter 75W-90 synthetic gear oil (BMW 83 22 0 397 114 or equivalent)
• LSD additive (only if limited-slip differential)
• New drain/fill plug crush washers

Procedure

1. Raise rear of vehicle on jack stands
2. Place drain pan under differential
3. Remove fill plug first (side of diff, 14mm Allen) — if you can’t remove it, don’t drain!
4. Remove drain plug (bottom, 14mm Allen)
5. Allow complete drainage
6. Reinstall drain plug with new washer — torque to 70 Nm
7. Pump new fluid through fill hole until it runs out
8. Reinstall fill plug with new washer — torque to 70 Nm

Tips

• Always remove fill plug before drain plug
• LSD differentials require friction modifier additive
• Check diff output seals for leaks while underneath