thumping noise

[homerun413]

I just got a 94 camaro the other day. Everything seems in perfect shape, its only got 70,000 miles, body is perfect and engine seemed in good shape. The only thing that is bothering me is when I am at speeds of 40+mph it shifts into a gear with a nasty loud thumping noise. No other gears do it. THis is an automatic. My dad said it might be when its shifting into overdrive but neither of us no anything about it. Any ideas? Is that kinda normal or should all thumps be checked out?

[Skullcamaro]

Mine does something similar. When I accelerate hard and it shifts into overdrive but I have to let off the accelerator quick it makes a thump/strange noise. I haven't been able to figure it out yet. I noticed it after I had my trans replaced at 90,000 miles thank god for extended warranty. Its definantly not the driveshaft or reaerend. I've either fixed or replaced them. The only thing I can think of is that its the trans releasing the extra load/power that is being held since it is suddenly not being used. Let me know if you find out anything about yours.

[homerun413]

Mine happens more when I am at about 40mph then I give it more gas up a hill, it does it when it shifts into gear. so it might be a lil different... but none the less keep me updated on urs.

[Skullcamaro]

I'll keep you updated. So far I've had my trans checked and its in good condition, no problems, etc. The driveshaft is new and the rear end was serviced a little while ago and a LSD was added. I was thinking that maybe its just a release of pressure for the internal solenoids in the trans but I'm not positive, my other idea was with the rear drum brakes. Its always hard to tell exactly where sounds are coming from. Maybe something in the drum brake releases and causes some kind of noise. Who knows, I'm still investigating it. I'll let you know what I find out.