About to change U-Joints

Before I dive into this project, I would like to get some affirmation from the community that I am on the right track here. If not, I welcome any other advice, including taking it to the dealer.

1. No off road, towing or misuse of vehicle, garage kept. 41K miles. Manual transmission

2. Neglected to grease U-joints for 36K until I read about it on this forum. Jumped right on it, and greased slip yoke at the same time. Retorqued rear diff flange nuts to 65 ft/lbs.

3. No play or obvious damage to U-joints, but the caps do not appear to purge evenly in terms of volume of grease escaping when pumping in the grease. The rear-most joint is the worst of the three.

3. After greasing (a couple of times already with Mobile 1 synthetic) I began to notice a slight "buzz" at 60 MPH when feathering gas to maintain highway speed. Smooth as silk up to that point. I feel the "buzz" in the shifter, gas pedal, seat and a bit in the steering wheel. Definitely NOT tires.... disappears when letting off gas, coasting in neutral or depressing clutch. Does not shake the wheel like an unbalanced or out-of-round tire would.

4. Have always had a slight/intermittent whine or howl in the drive line when feathering gas, but from reading about this in the forum, am not especially worried about it, and don't think it is related to the buzz I am experiencing.

MY OPINION: I'm thinking that I may have been a bit too late in realizing the need to grease my U-joints (36K), and that some minor bearing surface damage has already occurred inside a couple of the caps with the rest of them gliding normally following the introduction of grease. I'm thinking this is what may be setting up the slight vibration/buzz that I feel.

Thanks!

 

Just spitballing here.


Caps do not always purge evenly. I'd hit them a few more times before swapping just for that reason. How bad did the first purge look? Water or rust coming out?


I'd recheck the carrier bearing. Make sure that the alignment is right. When I installed drop shims, I was sure to align it using the witness marks on the mount from the original installation.

 

On first purge, just black, greasy gunk, but no obvious water or rust. On subsequent purges, got a mix of red grease from some of the (better purging?) caps and still black greasy gunk from some others. Getting nice red grease from all now, but in unequal amounts and not around the entire circumference of the seal on some.

I've never had the carrier bearing assembly out or dropped, so alignment shouldn't be a problem, right?

 

I would not bother yet with swapping them. It is unlikely that any of the rollers are bad?

Not that it fell, but just that the marks from the fasteners on the mounting flange are in the same spot as there is a slot in the flange. it might be riding a bit and giving you the vibes?

 

I wouldn't replace, I would just purge for a few times over a few weeks. Easy to do and should be fine. Grease lasts 36K miles.

 

Good to know on the life of the grease. I'll purge and monitor. Also checking carrier bearing marks. Thanks!

 

I don't see any evidence that the carrier bearing mount has moved, at least in terms of fastener position marks, but the LH side is about 1/8 forward of the RH side (slot shorter on LH side vs RH side). I would imagine that this is the factory-set alignment, but am not sure. Should I even them up?

 

Good stuff.

I assumed that you dropped that when you lubed the slip joint. I guess that you didn't?

 

Nope. Didn't have to. Pulled diff flange to drive shaft nuts, removed one Oetiker clamp from the slip yoke boot, pushed in on the slip yoke, and the rear portion of the drive shift separated ....now putting it back in was a different matter entirely. In retrospect, might have been easier had I dropped the CSB.