A worn wheel bearing on your BMW E90 (2006–2013) produces a characteristic humming or growling noise that changes with vehicle speed and intensifies when turning. US shops charge $350–$600 per corner to replace wheel bearings. With the right tools — most available on Amazon — you can do the rear bearing for around $80 in parts.
Diagnosing Which Bearing Has Failed
The noise changes character when you shift weight during turns:
- Noise louder turning LEFT → Right (passenger) side bearing
- Noise louder turning RIGHT → Left (driver) side bearing
On a straight road at 40–60 mph, the hum is consistent. Swerving gently left and right in an empty parking lot helps isolate the side.
Tools and Workspace Requirements
A hydraulic press is the main barrier to DIY wheel bearings. In the US, many AutoZone, O'Reilly, and Harbor Freight locations loan or sell 12-ton shop presses. Alternatively, a local machine shop will press bearings for $20–$30 — bring them the knuckle off the car.
Step-by-Step Procedure (Rear)
1. Loosen the Axle Nut
With the wheel on the ground, use your impact wrench and 30mm socket to break the rear axle nut loose. This is a one-time use nut — order a new one (about $5) before starting.
2. Lift and Support
Jack the rear of the car and place jack stands under the frame. Remove the wheel.
3. Disconnect the Brake
Remove the rear caliper (2x 13mm bolts) and hang it with a wire hook. Remove the rotor. Disconnect the ABS wheel speed sensor (7mm hex bolt).
4. Remove the Trailing Arm Bolts
The rear knuckle on the E90 is connected via the trailing arm and two lateral links. You don't need to disconnect all of them — just the two lower lateral arm bolts (M14) to swing the knuckle outward.
5. Remove the Hub and Bearing
Pull the axle shaft out of the hub. Use the BMW hub puller tool to remove the hub from the bearing. Then press the bearing out of the knuckle using the hydraulic press.
6. Press In New Bearing
Press the new bearing into the knuckle — pressing on the outer race only. Then press the hub back through the bearing inner race.
7. Reinstall and Torque
Reassemble in reverse order. Critical torque specs:
- Axle nut: 160 ft-lb (new nut required)
- Lower lateral arm bolts: 63 ft-lb (tighten with suspension at ride height)
- Caliper carrier: 45 ft-lb
8. Road Test
Test drive at 30 mph, then 60 mph. The hum should be completely gone. If you feel vibration, recheck hub runout with a dial indicator.
Brand Note for US Buyers
Use SKF, FAG, or INA bearings — all German brands widely available on Amazon USA. Avoid unbranded bearings from unknown sellers; BMW wheel bearings carry significant side loads that inferior bearings fail under quickly.