Thunk

[alfadoc]

On my relatively newly acquired 80 SC, there is a deep thunk emanating from the back when driving on bumpy roads. Reminds me of what a car that has suspension mounted to a subframe (Mercedes) sounds like when a subframe bushing is going bad. Any suggestions as to beginning diagnosis would be greatly appreciated.

[jpnovak]

Check the short list:

spring plate bushings. If old, they are likely cold-flowed to the point where the outer cover is riding on the spring plate.

Sway bar bushings - are they still good?

Sway bar mounting points. These are known to crack and will clunk afterwards.

[pors1968]

faulty sway bar link or loose upper shocks and check cv joint if bolt tight.

[ace123]

+1 on the sway bar especially if you hear the Thunk when turning.

[alfadoc]

Thanks all, I'll report back my findings.

[schumicat]

also check motor mounts.