New Uni Joint is too tight

[dom14]

I'm particularly confused by the difference in circlip thickness between the old and new one.
The groove width almost the same between two, yet the new one has a remarkably thinner
circlip. See the pictures and measurements.
I reckon that is NOT good.

[dom14]

Assuming above replacement uni joint is the accurate one,

It is indeed possible to crush needle bearings inside the cap and still manage to install the circlip by hitting it hard.

Especially in the above case where the circlip is lot thinner than the bearing cap groove.

[Robo]

I'm particularly confused by the difference in circlip thickness between the old and new one.
The groove width almost the same between two, yet the new one has a remarkably thinner
circlip. See the pictures and measurements.
I reckon that is NOT good.

58.47 new and old 57mm
Going by the measurements of new uni it's wider correct by 1.47mm.
but new clips only allow .63 mm less gap.
so extra pressure when compressed in place of .84mm tighter.
If Ive got it all correct.

pre grease inner of uni this helps to hold needles in place before assembly, can prevent em dropping out of position.
also ensures you have full coverage of the grease you want is in there, not just the factory assembly lube.

(just noticed you crushed rollers on page 1 not good,
but different measurements on page 2).

[mudski]

Overall length of the uni by what it is, is no drama. The flanges are open end so thats o.k. to a point. We know the cup size is right as you have pressed these in fine. The circlip groove distance measurement difference is compensated by the thinner circlip supplied. How accurate are your circlip groove measurements? Sometimes a little grease in the head of the cup can hold the cup out by a smidge. Put the new uni in a vice and squeeze the cups together and see what the measurement is.
What brand and part number are the new uni's? RUJ-2028 Is the number they should be. Which has a 28mm cup and 55.96mm from circlip to circlip.

[dom14]

58.47 new and old 57mm
Going by the measurements of new uni it's wider correct by 1.47mm.
but new clips only allow .63 mm less gap.
so extra pressure when compressed in place of .84mm tighter.
If Ive got it all correct.

pre grease inner of uni this helps to hold needles in place before assembly, can prevent em dropping out of position.
also ensures you have full coverage of the grease you want is in there, not just the factory assembly lube.

(just noticed you crushed rollers on page 1 not good,
but different measurements on page 2).

Yeah, I pregrease them, allowing the excess to ooze out while installing.
I'm putting back the old one, and see how it goes.
With good two needle bearings gone, the new is not that new anymore.
I just realized the old uni joint is actually far better quality one.
No pitting marks on the uni joint rod from needle bearings forcing on them.
But, all four uni joint rods have pitting marks on the new one from trying to undo it.
I'm learning a lot, but overall the replacement job has been an unnecessary job, considering
the condition the old one is in.
It's lot easier to drop the needle bearings or force them into wrong position than I earlier thought.
Uni joint replacement need lot more care and patience than I thought.
Good lesson for sure.

[dom14]

Overall length of the uni by what it is, is no drama. The flanges are open end so thats o.k. to a point. We know the cup size is right as you have pressed these in fine. The circlip groove distance measurement difference is compensated by the thinner circlip supplied. How accurate are your circlip groove measurements? Sometimes a little grease in the head of the cup can hold the cup out by a smidge. Put the new uni in a vice and squeeze the cups together and see what the measurement is.
What brand and part number are the new uni's? RUJ-2028 Is the number they should be. Which has a 28mm cup and 55.96mm from circlip to circlip.

I just took these measurements of pictures to make sure. This is the new replacement one that I've managed to break few needle bearings above. I bought it from Bearing Wholsalers around two years ago.
It appears to be the correct part number, except the distances are 58.42mm outer edge of the groove to outer edge or 53.42mm(58.42-5) inner edge of the groove to inner edge.
If the "Circlip to circlip distance" means the same thing, then 55.96mm distance is only right if we take the given circlip(1.5mm) thickness into account. In that case, 58.42-3=55.42mm. There's still a difference of 55.96-55.42=0.54mm.

The real bummer is that I can't scavenge couple of needle rollers from the old one 'cos they are different size.
New uni joint is useless unless I manage to find couple of needle rollers of same size from somewhere.

[dom14]

I put the old uni joint back in with plenty of grease.
It's moving lot better than before.
I think I learnt few lessons.

1)Lot of care should be taken to ensure the needle bearings don't go out of place and get lodged in the back of the uni joint bearing cap
2)If it's too tight, uni joint should be pulled out to make sure nothing's gone wrong inside.
3)Don't fix it if it ain't broken. (In my case the removal was kinda worth it 'cos I learnt to do the job properly and also managed to regrease the old one, as it wasn't possible to regrease it without pulling it out[no grease niple])

As for the new replacement bearing, I'll have to see whether I can scavenge couple of needle bearings from an old one from somewhere. Even if it's not reliably usable, it's still worth keeping it for future spares I reckon.

[micktickner1980]

Always fit the uni dry (no grease) they should nearly always feel tight. Grab a decent size hammer. I use a 7lb one and flog the living christ out of the yokes directly. Dont put a piece of wood in between as you wont get the force required to seat the caps home. You really have to give it a good hard swing and hit. Dont be scared! you wont break it.

Then Lube the unit with a super tacky grease like Moreys Big Foot until the seals pop.

PS. Hardy spicer brand universals are absolute rubbish. I would never use another again. I only use the OEM Japanese ones.

[mudski]

I put the old uni joint back in with plenty of grease.
It's moving lot better than before.
I think I learnt few lessons.

1)Lot of care should be taken to ensure the needle bearings don't go out of place and get lodged in the back of the uni joint bearing cap
2)If it's too tight, uni joint should be pulled out to make sure nothing's gone wrong inside.
3)Don't fix it if it ain't broken. (In my case the removal was kinda worth it 'cos I learnt to do the job properly and also managed to regrease the old one, as it wasn't possible to regrease it without pulling it out[no grease niple])

As for the new replacement bearing, I'll have to see whether I can scavenge couple of needle bearings from an old one from somewhere. Even if it's not reliably usable, it's still worth keeping it for future spares I reckon.

Lesson 3. Nothing wrong with preventative maintenance....

Always fit the uni dry (no grease) they should nearly always feel tight. Grab a decent size hammer. I use a 7lb one and flog the living christ out of the yokes directly. Dont put a piece of wood in between as you wont get the force required to seat the caps home. You really have to give it a good hard swing and hit. Dont be scared! you wont break it.

Then Lube the unit with a super tacky grease like Moreys Big Foot until the seals pop.

PS. Hardy spicer brand universals are absolute rubbish. I would never use another again. I only use the OEM Japanese ones.

Dom used a big hammer and had shatter a couple of needle rollers... Whats your reasoning behind Hardy Spicer? I dealt with and sold their product for over 20 years in the heavy transport industry. Never had one issue.

[dom14]

Always fit the uni dry (no grease) they should nearly always feel tight. Grab a decent size hammer. I use a 7lb one and flog the living christ out of the yokes directly. Dont put a piece of wood in between as you wont get the force required to seat the caps home. You really have to give it a good hard swing and hit. Dont be scared! you wont break it.

Then Lube the unit with a super tacky grease like Moreys Big Foot until the seals pop.

PS. Hardy spicer brand universals are absolute rubbish. I would never use another again. I only use the OEM Japanese ones.

Sorry, I have to disagree with the above. I did exactly as above and got headache results.
I fitted the new uni joint with the existing grease in it and didn't add anymore, thinking I grease it with the gun after finishing it.
I banged it really hard to loosen it up when it was too tight. The results speak for itself with the above photos.
I also took "enough" care to make sure the needle bearings don't go out of place, but it wasn't enough with lack of experience and NOT enough grease
inside the caps.
You can also see the pitting marks on the bearing rods from the needle roller, which were caused by banging hard, which also indicates that these replacement
uni's which aren't the same as factory originals are better off pressing, provided we have access to a press, but it's doable with a big enough bench vice though.