I have a bad vibration which sets in under throttle at around 75mph. It disappears when I back off the throttle. I have just bought the car and the previous owner has a receipt for a part called "propshaft coupling kit", and I am not sure whether it was the back or front!

This vibration is felt throughout the car at speed, there is an annoying droning noise as well as a feeling coming through the seats and steering, all the wheels have been balanced.

I jacked up the rear of the car at one side and there is a fair amount of freeplay/slap at the rear diff when you rotate one rear wheel with the other on the ground. I am sure the rear diff also make a slight whining noise at low speed, almost like a failed wheel bearing.

The rear flex disk looks in good condition.

With the transmission in park and rotating the jacked up rear wheel I can see the propshaft rotating at the large circular vibration damper behind the transmission flange, but there seems to be quite a lot of freeplay between this and the flex disk attached to the transmission flange. I take it that this means that the front flex disk worn out as I suspect there should be no play. There is also a sligh rubber squeaking sound like a mouse from aroung this area. My friend's 190e has no play at this point. Will replacing this front flex disk cure my vibration problem??

Thanks in advance for your help.

Doug
London UK

Thanks for your help