Diff mounts will give you a clunk when shifting. Look at your suspension links. At lease one pair (left and right) out of the 5 sets need to be replaced. Any that have the rubber end bushing that looks like its oozing out of the housing should be replaced. Follow the service manual procedures (final tightening done with the suspension on the ground or on a ramp, wheels loaded with car weight).

__________________
Hanno
'79 6.9 Sold (after 27 years)
'83 280SL, 5 spd.
'94 E320 Sdn. 5 spd conversion
'02 E320 Sdn.(on loan to mom!)
'87 300E (5 spd. conversion) Sold
'05 E500 Wagon