Mercedes-Benz W140 steering wheel vibration
Why does the W140 steering wheel shake at a certain speed?
The cause is usually wheel runout, a bent rim, worn suspension joints or a wheel bearing. Even a vertical runout of a few millimetres is felt in the steering wheel, and it can be seen when spinning the tyre. Balancing does not necessarily remove the runout.
What is checked if the vibration continues after new tyres?
Check the dent on the inner edge of the rim, the lower ball joints, the lower control arm bushings, the anti-roll bar rubbers, the tie rod joints and the steering knuckle. The wheels are also worth rebalancing. The cause is often found by replacing the worn parts. Steering and suspension parts are safety-critical, so have a workshop inspect them.
How does a wheel bearing fault show up on a W140?
The bearing can cause vibration and the car pulling to the side. When the bearing falls apart, smoke may rise from the hub and grease may leak out, but no noise is necessarily heard. The bearing and the stub axle are usually replaced together.