Auto 350 question

[Tweek]

I'm replacing all U joints, wheel bearings, and bushings in my 80 Vette, it has become quite a project! I noticed tonite that there is slight movement in the rear of the trany, that I thought before was the front U joint in need of being replaced... so how much play is normal in the rear of this trany, and if not, is there a bushing in the rear of the trany that can be replaced without pulling the hole transmission....or do I have more work to be done

 

[page62]

Can you be more specific? Here are 3 choices...

Does the whole tranny move around? If so, your tranny mount may be loose or just plain shot.

Does the tranny yoke move? Your yoke may be worn out.

Does the tranny tailshaft move around without the yoke on it? That's normal.

 

[Tweek]

The driveshaft is still in the car, no bolts have been removed. The movement is in the tail shaft / yoke. I can move the drive shaft up and down, and side to side at most a 1/8th of an inch. I first though it was the U joint. I don't think it is the spline/ yoke connection, but the shaft that is inside the trany that is moving

 

[hotrodd]

Sound's like maybe the tail shaft bushing.Easy fix.Worth checking.

 

[Tweek]

Can this be done while the trany is in the car, by removing the tailshaft?

 

[page62]

...and the seal isn't leaking?! You may want to consider having a tranny shop look at it...after all, estimates are free!

 

[cntrhub]

Yes, there is slight "float" at the yoke and output shaft of the Trans. No need to remover the tail section to remove the seal. Check where the outer yoke touches the seal, and make sure there's no groove to cause a leak. If you see damage to the yoke's sleeve contact, then yes, you can remove the tail section without removing the Trans. The Trans may need to be elevated a little for clearance. Careful not to use the output shaft as leverage to remove the seal, if you find the yoke sleeve ok. If the sleeve needs replacing, you will need a press, and/or an adapter to R&R the sleeve. Use a new quad 0-ring at the tail. Remove the drive shaft, and inspect the yoke first. Don't forget to mark the driveshaft at the rear end. If you reinstall the d/shaft and are 180 degrees out, you may offset the balance. The tail seal replacement is a piece of cake. Make sure you use a leather mallet to the new seal and carefully tap it in square. Tapping in a circle, gets it home. If you have a seal driver adapter that has the correct diameter, you can make the job easier. Either way works well. Do not remove a little bead of sealer around the new seal. If using a mallet, try not to deform the lip seal, or distort the seal's housing. A little bit of Trans oil will be lost when pulling the shaft and the seal. Remember to top off the fluid when done. When reinstalling the shaft, use lithium grease, and apply evenly to the yoke's inside teeth. . Use either clean Trans fluid or a little lithium grease on the outer yoke for the new seal.

 

[Tweek]

Hey thanks for all the help, I did check the seal today, I must replace it, everything else looks fine. I do have one worry though, when you said about marking the drive shaft, and it being 180 out of balance. I have the car torn apart in the rear, and I know I have spun the rear half shaft yokes checking for play with the drive shaft out, and never marked the rear at the driveshaft, or the half shafts. The half shafts don't have any balance weights on them, but the drive shaft does, and as I said from the begining of the post I have changed all my U joints. What now, try it and see, if there is vibration, switch the drive shaft?

 

[cntrhub]

Exactly. You only have two choices. So right now, you have a 50/50 chance it's on like before and hopefully no vibrations. You know the rest.