I went to look at this '91 RS for a possible winter car. it's got the 305 114,000 miles. Guy tells me it's got this thump that it does usually when there's at least 2 ppl in the car and you get on it. So we go for a ride- I punch it and he says, "did you feel that?" and I did feel a thump but I wouldn't have noticed- just felt like transmission shifting. He says he had it looked at and the guy told him it was probably some brace that goes bad and does that- says he's replaced a lot of them on "these cars." Any thoughts???

Transmission mount needs replacing.

that's a new one on me

it's pretty common. replace it with a ES poly mount and you'll nevre replace one again

how much to have that fixed???

I had mine replaced and I don't think it was any more than $20 Canadian or so... its a cheap and easy thing to fix... think it took less than 15 minutes

ok, thanks for the info, guys

I fixed my Trans. mount for less than $15. Took about an hour, all the bolts were stuck though(took some perswasion, if ya know what I mean). Just backed the car up on ramps, jacked up the transmission alitle(loosen the lower nut first), mine was in two pieces so I just droped the bottom half out and went to work on the top bolts. Solved the thumping problem, might have even increased felt torque, could just be imagining things though.


Max.

Sounds like the tranny mount bushings on the crossmember might be bad. The X-member will have two parts; the main crossmember and an upper part. There are four bushings in there that absorb the shock of the tranny shifting. The driver's side of mine were non-existant when I bought my 82, and I got them from a dealership for about $40 for the set. Prolly would have been cheaper to have gone aftermarket, but hey, I needed them fast, and there was no more "CLUNK!"