Replace engine and transmission mounts -- a bad transmission mount will cause a thumping or drumming vibration on acceleration due to excessive up and down movement of the transmission.

I would also check the rubber mount for the driveshaft center bearing if you have one, as well as for play in the universal joints in the driveshaft.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!