After installation of a donut shaped isolator around the driveshaft(layman's terms), the car now exhibits a pulsing sort of thrumming feel between 85 and 95 KPH. It is not noticeable below this speed or above 100Kph. It has been suggested that this isolator is too tight. It is ostensibly there to prevent a tendency to clunk when Drive or Reverse is engaged, from a rest position. The wheels and tires are fine and the car is otherwise great. Low mileage of 115,000KMs. The suspension and front end has been fully updated and serviced.
It was not there before this 'donut' isolator was replaced. Any ideas?

al

If the driveshaft was taken apart at the spline in the process without marking its relationship and reassembling it by aligning the marks, the driveshaft could be out of balance. If that were the case I would think it would be at all speeds, but it might cause what you describe.

Note that it is not necessary to completely disassemble the driveshaft at the spline to accomplish replacement of the flex disk, but it is very possible that it happened.

Otherwise, you need to see that the center carrier bearing is in good shape and the bolts are tight. Also wiggle the u-joint while you're there. Check everything driveshaft related since the vibration started at that point.

Good luck,

For Larry Bible,

Many thanks. I will have the garage check out this possible reason for the odd thrumming. I have lots of experience with my 300E getting it serviced in Japan, Barbados and Canada, and some of the service work was scarey!! Thanks again.

Al
Vancouver Island, Canada