Mercedes-Benz W123 driveshaft rumble and vibration
Mercedes-Benz W123 driveshaft rumbles or vibrates at a certain speed: what causes it?
The most common causes are a worn driveshaft centre support bearing and its rubber, a broken vibration damper, worn flex discs (rubber joints) and poor driveshaft balance. The vibration is usually felt only in a certain speed range, for example 50–90 km/h.
What should I check on the W123 driveshaft first?
1. Vibration damper: it must have no cracks, and the rubber must be firmly bonded to the metal. 2. Centre support bearing and its support rubber. 3. Flex discs and the universal joint: cracks or play. 4. Tightness of the centre nut: a nut that is too loose can rumble. The rubber mounts under the driveshaft and the gearbox also wear often.
What should I remember when removing and refitting the W123 driveshaft?
Mark the relative position of the front and rear sections and the gearbox flange before removal, and refit with the marks aligned. The driveshaft is balanced as a complete unit, so a wrong position causes vibration. It is worth replacing the support bearing and the support rubber together. Balancing is a job for a workshop.
Should W123 driveshaft rumble be fixed straight away?
Yes. A driveshaft rubber joint that has rumbled for a long time can break completely, and this can also damage other parts. If the driveshaft is fine, the vibration can also come from the engine or gearbox mounts or from a wheel.