I took my '94 TA to the shop today to have a leaking pinion seal replaced and the rear end fluid changed. I got the car back and noticed that when rolling in reverse I'm getting loud clunks periodically that feels like the rear end gears are jamming and popping loose. When I hear the clunks i can feel the vibration through the car. I am not talking about the clunk that you hear when shifting from drive to reverse, this noise occurs when the car is rolling. This is an automatic 2.73 and the problem only seems to happen in reverse. What could the shop have done wrong? The only thing they had to do was disconnect the prop shaft from the differential case to change the seal, is there anything they could screw up that would cause a problem like i'm describing? Could changing the fluid cause problems to show up? I will take the car back to the shop, but does anyone have suggestions?

 

They may have not tightened the pinion all the way. Alos the driveshaft could be loose also.

Jeff

 

I was just testing the car out again, and the clunking is also occuring when the car is rolling forward. Also the clunking only seems to happen when you let the engine idle in drive or reverse and let the car roll slowly. I have not notice any noise at higher speeds.

 

Going straight ahead or turning?

 

The clunking is happening when the car is going straight.

 

I would say they didn't tighten the pinion nut up enough...

I've dealt with it before... sonds exactly like it...

but... they may have tightened it up adn it may have come loose, those are locknut's and aren't supossed to be reused... although sometimes you can get away with it. Normally I use them twice then replace them.

 

Check with the shop to make sure they put some GM limited slip additive in the rear end when they added new oil.

Without it, you will experience some harsh sounds coming from the axle housing.

 

If the pinion is actually loose, you could be in danger of busting up the gear set. The shop should look at it again.

LSA should not be a factor for noise when you are going straight (that's why I asked).

 

I second this notion, since you are only experiencing it at slow speeds. I'd hope the shop is competent enough to tighten stuff. Never know I guess.

-Dave