How Tight is Too Tight?

[65 Dartman]

An acquaintance stopped by yesterday with a driveshaft with a U joint mostly installed. He had the caps pressed in and one of the lock rings installed but not the other one. He was asking my opinion cause the U Joint will hardly move. My opinion was that it ought to move more freely than what it’s doing. So, how tight is too tight?

 

[Desoto291hemi]

It should move with no effort at all

Tommy

 

[Dartswinger70]

Not sure about the tightness but I have found if you cant get the cup pressed in enough for the lock ring, a needle bearing has fell out of the side of the cup and is stuck in between the U joint and the cup itself preventing it from being pressed further. Its fairly easy to do as Ive seen it more than once I use a a gob of grease into the needle bearings to keep them "glued in place"

 

[318willrun]

An acquaintance stopped by yesterday with a driveshaft with a U joint mostly installed. He had the caps pressed in and one of the lock rings installed but not the other one. He was asking my opinion cause the U Joint will hardly move. My opinion was that it ought to move more freely than what it’s doing. So, how tight is too tight?

so many different brands of u-joints and thicknesses of lock rings... I've just always used a file to take a little off the inside of the drive shaft "loops" so the lock rings fit. Usually only a coupe thousands per side fixes it right up

 

[33IMP]

Not sure about the tightness but I have found if you cant get the cup pressed in enough for the lock ring, a needle bearing has fell out of the side of the cup and is stuck in between the U joint and the cup itself preventing it from being pressed further. Its fairly easy to do as Ive seen it more than once I use a a gob of grease into the needle bearings to keep them "glued in place"

Correct answer. IMO.

 

[Professor Fate]

If everything looks okay otherwise (no errant needle bearings), take the driveshaft and lay the yoke on your anvil (or vise) and give it a couple of smart whacks with a medium hammer (nothing huge). Rotate it and repeat on the opposite side, then do the same on the other two caps/yokes. Then do the same on the other end of the shaft. You're not trying to beat it into submission, here- just relieving some tension that may have been applied when the joints were pressed in. I've had them loosen right up after a few judicious smacks.

 

[65 Dartman]

Thanks for the replies. I told him he might have to press it apart and make sure everything was OK inside the cups as far as the needle bearings was concerned. He said he might try that. Said he’ll let me know