Something is loose

[85MustGT]

Sounds like my muffler is banging on the floorboards when I go over any bump. So I took it to a muffler shop and they put it on a lift and the exhaust is tight. We began wiggling stuff but could not duplicate the thunk. The car has welded subframes and they look good. The car drives just fine except for the thunk.

 

[bakos24]

Check the part of the exhaust that goes up over the axle. Usually it is to close to the floor boards and hits going over bumps. You can fix it by adjusting the pipes.

 

[85MustGT]

Check the part of the exhaust that goes up over the axle. Usually it is to close to the floor boards and hits going over bumps. You can fix it by adjusting the pipes.

I will check that out.

 

[86bluecobra]

You check to see that your tranny mount is in good condition?

 

[85MustGT]

You check to see that your tranny mount is in good condition?

Nice, I will check that out.

 

[96SCstang]

probably the sway bar links, bud. They make a clunk noise over bumbs when they go bad. this would be my guess without hearing it for myself