When I come to a stop, maybe when I'm down to 7 to 13 MPH, I get a clunk that seems to be in the rear, but sometimes I think I feel it up front, as in opposite ends of the driveshaft. This happens during normal stop and and go driving. If I roll really slowly to a stop, it doesn't clunk. I was thinking u-joints at first, so I pulled the driveshaft, but those were fine. I replaced my stock steel shaft w/ an aluminum one that also had sound u-joints, cuz I was gonna do this anyways. The transmission seems to be shifting fine, but I'm just not sure. Tranny mount looked good, and I replaced one bad motor mount . I did pick up an 89 9 bolt posi disc 3.27 rear end to replace my stock 3.08 open drum, so it wouldn't be too bad if it was the rear. Any ideas? What do I look at next?

 

tranny mount

 

Nope. I replaced that now, too. The old one didn't look too bad when I pulled it, just a couple small cracks but none around the edges of the rubber. So I put a new one in, just a normal cheap rubber one, and still the same problem. Seems to clunk more when I'm at a stand still and I shift it from drive to reverse, drive to reverse, etc. also. Reminded me of bad U-Joints, but like I said, I checked those. The new transmission mount when in easy, and is the same as the old mount, so that shouldn't be a problem. Just because it's a cheapy doesn't mean it shouldn't work properly. So what's next? Torque arm? How would I go about checking that the torque arm? I haven't messed w/ them before. Any other ideas?

 

Try to lift up on the TA and see if the bushing is worn or just softened from fluids. It sounds like a TA problem since it only happens when the drivetrain is loaded or being unloaded. Try shifting from 1st to reverse with the brake on and have someone look underneath.

 

my bet is on the Torque Arm Bushing. That exact thing used to happen to my car ALL the time. Reverse would clunk, drive would clunk, and when the car would downshift on its own (coming to a stop), it would clunk slightly. Took me forever to finally figure it out. Get underneath the car, the torque arm runs right beside the Driveshaft, and bolts to the rear end. The other end is connected to the tailshaft of the tranny. It slides into the rubber torque arm bushing. Just try to pull the torque arm up and down and see if you hear that clunk. If so, the bushing is probably shot. It shouldn't be able to slide up or down at all.

Good luck, my money is on the bushing.

 

oops, guess graebz28 beat me to it....

 

i am having the exact same problem with my car. I have a new poly tranny mount and a BMR TA with a new poly bushing so i am assuming those arnt the problem. Ill probably have my U joints changed this week, ill let u guys know if the problem was fixed or not.

 

okay, i'll be checking the torque arm bushing tomorrow then. are they difficult to replace?

 

as long as you have the right tools, they aren't too bad.

if you take the torque arm off, it makes it alot easier.

 

Mine klunks like that, but only not when in overdrive, but it is do to my new High perf internals. Its got corvette internals in the 700R4. So its normal for mine, just had all that stuff checked too, so if youv'e changed your tranny or got something more high perf in there, maybe thats doin it? just a though!

 

hey hey same problem here guys. Clunk from under the car when decelerating. Just got my broken trans mount fixed but havent looked at the ta bushings. I also have a vette servo and heavy duty clutches in my trans. So is that normal with the corvette internals or can it be fixed with the bushings? Its the exact problem u cuys are having. Any luck in fixing it?

 

a GM tranny with shift kit and corvette servo will go into gear hard. that is normal. Mine does the same thing (th700r-4). It makes it last longer believe it or not

cheers!

though if you dn't have either of those things and you have a clunk, check your mounts,u-joints, and maybe the rear end. You never know and better to be safe then sorry!!

cheers

 

I have the same problem. My car would have a small clunk when I decellerate to stop while in drive. However it doesn't do it in overdrive. It did it ever since I changed the rear gear ratio from 2.73 to 3.42. I have replaced the trans governor with lighter weights to correct the shift points for 5800 rpm. I've also repaced the U joints and torque arm mount, panhard rod, and LCA bushings. Someone I have talked to said that I may have not used the correct inner spring in the corvette servo. But so far it has been almost 6 years and it works.

 

i havent seen this post in while. anyways i did kind of find out what my problem was. i replaced the motor mounts, torque arm bushing, tranny mount, u joints, and did a tranny fluid flush partially because its all cheap stuff anyways. i thought it would be the ta bushing. anyways, it still clunked as i described above. i don't have a shift kit as far as i know. i did notice that it only clunks when i'm in drive, and not when im in overdrive. i talked to a friend of mine who runs a tranny shop and he said there was a GM defect in the tranny(i don't know if this is what was improved upon in 87), something about calibration, the servo, and something else. I don't know anything about the internals of a tranny so i can't say for sure. He said that its nothing to worry about really and I should just drive in overdrive. So that's what I've been doing and its been fine. Anyone know what this defect actually is? Or what changes were made in 87?

 

sorry i'm posting three years too late, but I have an 87 with the same issue.

 

ya 3 years late here as well. I also have a problem like that, but I also have it when I turn sharp slow or normal, I hear clunks. Ex: I'll be leaving work, so I stop at the stop sign make a 90 degree left turn and I'll here a clunk, I'll go over the two speed bumps next to security and clunk clunk. No noise when I'm on the freeway Only making turns. Its a clunk like metal or something pretty hard it's really Imbarassing, almost makes me not want to drive it anymore.

 

Sounds like maybe a suspension bushing is missing.

 

mine does it whenever I decelerate in third or stop in third. I can hear the tranny downshift then a clunk noise. I never knew what it was but I didn't worry too much about it.

I have an Energy Suspension Polyurethane tranny mount. So far its been holding up pretty good

 

Me also I have the same problem, in end of decelleration to stop in D, I have a little clunk, I have changed transmission mount but not resolved, but I haven't this problem in OD, level oil mean ok and cable tv also ..... that 's a riddle .... ?