spedaleden

1981 manual with 5 speed

I rebuilt motor and have a vibration in drive train at 70 mph. At 70 push the clutch in and you can still feel vibration. It feels like vibration is at the yoke of the trans. Pulled drive shaft and found missing needle bearings in u joint at trans. Would this create a vibration?





Also what is the U joint used on a tremec tko 600

7T1vette

I doubt that is the cause for your vibration. Does the vibration get worse as speed goes up? Have you tried swapping front tires for rears to see if tire balance is the culprit? Tires lose wheel weights all the time, when the wheel hits a good sized bump. Also, try to shake the rear half-shafts to see if there is any looseness there. And, it could be simply due to the driveshaft; it needs to be balanced, also. Inspect it to see if there is a 'missing' [welded-on] weight from the shaft.

rberman999

I'd say if you're missing needle bearings then yes that can cause a vibration. As a U joint wears out the needles fall out and once things get bad enough the joint starts to clunk. Prior to clunking the bad joint will manifest as a drive line vibration. One way or another the first thing I'd do is replace the U joint with a fully functional joint before doing anything else. Lots of luck, Russ.

7T1vette

With ONE needle short, it's unlikely that you would ever notice the difference. It was probably assembled with a missing needle bearing and has been working fine ever since.

I've seen U-joint bearing caps that had NO needles left in them...only rust-dust and damaged surfaces. And there was no obvious malfunction of the drivetrain. Maybe just an annoying vibration, but not how you would expect such a damaged bearing to act.

Visually, that bearing cap looks about the same as one with all the needles present. Obviously, you should replace it. But that's not going to solve your problem.

rberman999

Actually if you examine the photo carefully you can see several needle bearings missing. I might agree with you with only one missing but once several are gone(as can be seen in the photo) then all bets are off. The bearing should be replaced, always start with the simple / obvious things link a U joint that isn't assembled correctly. Once something know to be incorrect is fixed move on from there. Lots of luck, Russ.

spedaleden

New joint helped but did fix it. I had a pinion angle also. I raised trans and it much better, going to raise some more and see if I went to far or gets even better.

7T1vette

I think you meant to say that changing the U-joint didn't fix it, but that the driveshaft angle may have been excessive. Those joints can only handle so much angle offset without causing some binding and resulting vibration. So, I think that was the majority of your problem. What you feel is a combination of ALL sources of vibration in the drivetrain; and there might be several contributors to that vibration. Without doubt there will be some vibration due to tire unbalance, wheel unbalance, shaft unbalance (no part or system is perfectly balanced) and vibration due to driveline offsets.

spedaleden

OK after playing around with everything, vibration is gone. It was u joints in drive shaft and half shafts. I pulled rear end to check for leaks and all good, shot it with a new coat of paint and back together it went. I removed poly bushing for front of diff mount and replaced with rubber.

SLVRSHRK

You mention that your car is a 5-speed in the first post. I'm going to assume that is an add-on (like mine, great mod).

Is the vibration in the shifter? If so, it could be the driveshaft angle. I had a similar vibration in my original drivetrain which I fixed by replacing the front rubber mount on the rear diff and getting the angle set correctly.

Additionally, when you do a 5-speed swap, you should have set the driveshaft angle accordingly. A misalignment here could cause a vibration (mine was up around 70 as well BTW).

Plenty of posts on driveshaft angle so I won't post it here, just do a search.

Good Luck!

spedaleden

Keisler 5 speed Tremec and shifter was shaking like no tomorrow. I did play with drive shaft angle but vibration was a little better but I was not happy. Once I replaced half shaft u joints and put trans back to original angle it is smooth as butter. No vibration in shifter, you can barely feel the gear movement from the trans in the handle at 90mph. As smooth as my sons C5

I also removed poly from mount on diff and replaced with rubber. I joy to drive again.

Big2Bird

I wouldn't think that would make any difference.

TimAT

TREMEC has a great little Android app for checking driveline angles. Start the app, place your phone against the front yoke, push the button the repeat for the rear, It calculates the angles and tells you if it's within limits or not.

spedaleden

I agree but at the time wanted the vibration gone and tried everything I could think of.

spedaleden

Have it and used it.