clunk in differential

[DaveKayson]

I had a vibration in the drivetrain. I bought all the parts to rebuild the torque tube and did so. I used the heavy duty bushings and put in a new bearing. Still have noise. You advised me to see if the top stop had come off. It hasn't.

I drained the diff oil and took the cover off to examine it. I couldn't see any chipped teeth or feel anything in the bottom off the case. I refilled it with 85--140 gear oil.

While the car was still up on jack stands I crawled under it and had my son go through the gears. There is a clunk where the torque tube connects to differential. It's in the front part of the diff. As soon as you let out the clutch I'll hear the clunk. Could I have messed something up when I put the torque tube back on? The 4 bolt connection is tight. When I look at the Opel manual, it shows the shaft inside the torque tube...inside the splined tube appears to be 2 round spacers and a thrust cap before the pinion preload nut. I don't remember seeing anything like that in mine.

Secondly while on the stands if I rock the rear wheels back and forth I get a fair amount of play. I don't know if that's normal or not. I think probably not.

Your thoughts and suggestions would be greatly appreciated. If I need to start looking for a used rear axle I start but don't really want to go through the work if that's not it.

It's a ' 73 Gt.

Thanks,

Dave Kayson

[greensmurf20]

to answer your 2nd question, when my GT is on the ground and you push on the quarters of the car, the axles have play and i am told this is normal. if you end up needing a rear axle, i have one complete minus the brake hardware but still has drums and backing plates.

[kwilford]

Do you have the propeller shaft compression spring in place (that sits in the transmission tail housing and pushes the propeller shaft towards the differential)? I have heard that if this is left out, the propeller and drive-shaft (the first is the front shaft with the U-Joints, the second is the thin rear shaft that rotates inside the torque tube) can slide forward. Then the drive shaft splined collar doesn't fully engage the differential pinion drive, and the splines can wear. And it will "clunk" when loaded.

Remove the propeller shaft and confirm the spring is in place. It's a LOT more work, but also remove the torque tube to see if the drive-shaft splines have worn.

The Factory Service Manual also says that a clunk on acceleration can be caused by "a worn differential cross shaft in case". But that requires a complete differential tear-down. Which is where you may be headed.

This has been a MARATHON problem. Good luck and I HTH