UJ Replacement

UJ Replacement

Author
Discussion

adam quantrill

11,538 posts

243 months

Thursday 1st October 2009
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I'm doing this now on the 400SX - driveshaft still on car - the old one needed a little persuasion but is almost off now.

The technique is a little different to trailing arm - you really need to jack up the suspension so that the driveshaft is as slack as possible before starting to hit things with a big hammer.

ed_crouch

1,169 posts

243 months

Thursday 1st October 2009
quotequote all
I took mine off the car and the UJs needed a f***ing good thrashing to remove the old ones. Bust a 6 inch bench vice too...

I would just remove the shafts, I really would. You risk damaging the diff output bearings by doing it on the car unless the UJ caps just fall out. If its got the larger spec shafts (390SEs and upwards)you'll need an 11/16" AF socket, either thin-wall 1/2" drive or a GOOD 3/8" drive (preferably single hex, so an Elora, snap-on or the like) socket to get at the driveshaft flange nuts cos the inboard yokes run quite close to the nuts. You'll also want to angle the shaft away from the nuts you're trying to undo to get the clearance..

If you're as anally retentive as me you might consider dropping the whole rear subframe to recon the rear brakes, check the diff beam isnt broken (they can break if you turn into the Stig at the lights) and shinify everything. Diff is a proper boat anchor though so be careful.

I wrote an article on my experiences doing this. Gis a shout if you want it and I'll email.





adam quantrill

11,538 posts

243 months

Thursday 1st October 2009
quotequote all
Alas my bench vice is no more either after I tried pressing out a bearing shell from a trailing arm ;^(

The UJ cups weren't too bad, and it's the outer UJ so I think the diff bearings will be fine. It's no worse than what happens when the wheel goes over a pothole anyways. Besides, it's almost out now so I'm not going to touch anything else - visions of a 10 week rebuild spring to mind!

I found that (with the UJ on the car) an efficient way of getting it out was to jack up a bit under the driveshaft and whack the top cap with a club hammer via a socket, which pushes the lower one out. Use a block of wood tween the jack and the driveshaft to spread the load. Turn the shaft through 180 and repeat but with a socket right in the hole where the cup was.

adam quantrill

11,538 posts

243 months

Thursday 1st October 2009
quotequote all
45 minutes and the new one is back on. I had a small scare when one of the bearing cups wouldn't go in but it turned out that it was bottoming out on the spider. Jacking up the driveshaft again did the trick and it was tapped home quite easily.

I didn't fall foul of any pins dropping out while the cups went back in so all is well. I gave it a good greasing too so hopefully this one will last a good 30k miles.

Looking at the old spider it's all rusty on the failed bearings, which is the usual problem, water ingress and the needles start to rust and fail.

adam quantrill

11,538 posts

243 months

Friday 2nd October 2009
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All in all I think replacing on the car is easier with A-frame suspension than with trailing arm.

I used a GKN equivalent to the HS179 which has part number 7.886.00.06.18.200 and does come with a grease nipple. Looks like a good quality made unit.

adam quantrill

11,538 posts

243 months

Tuesday 19th January 2010
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Just done the other side outer one at the weekend! I wish I had read my own notes here first, might have saved a few minutes here and there, as I had forgotten one of the tips. Doh! Jacking up the driveshaft a bit really does the trick.

adam quantrill

11,538 posts

243 months

Sunday 18th May 2014
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Just done an inner one. There's more to it than the outer ones.

- Don't try to do it in situ as any whacking could affect the diff bearings. Besides there isn't enough room to swing a toffee hammer, let alone a 10lb club hammer.
- Remove wheel and jack up suspension a bit.
- Undo the 4 driveshaft nuts at the diff end.
- Undo the tie bar at the hub.
- Slacken the hub mounting bolts fore and aft.
- Lower the suspension a bit.
- With a bit of jiggling and prying the drivehsft will come off the bolts and the hub carrier can be swiveled outwards almost 180 degrees and the whole driveshaft will stick out of the car.



- It's just the right height to put a bench vice under to start whacking things and extracting the bearing cups.
- Clean up the holes left by the old bearing and make sure the new cups will fit OK then reassemble.
- If you can't get the tie rod bolt back in grind it a little bit to make the end pointy.



Edited by adam quantrill on Sunday 18th May 20:47

MrPicky

1,233 posts

268 months

Sunday 18th May 2014
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Don't forget to mark the flange and the disk and also the way the yokes fit into the two ends of the driveshaft.

If it was balanced before you start that will ensure that it is still balanced.

Russ

adam quantrill

11,538 posts

243 months

Sunday 18th May 2014
quotequote all
I've never bothered with this and never had a problem - maybe I've been lucky every time?

As the rear driveshafts are on the cock most of the time I don't think it matters. Probably an issue for the propshaft though.

adam quantrill

11,538 posts

243 months

Sunday 2nd October 2016
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Just done the outer again on the same side, so it lasted 2009-2016 = 7 years * 7k = 49k miles, I suppose that's not too bad.

One thing I didn't put in the advice is to remove the grease nipple before removing the UJ - I forgot this and it smashed off, but it would have been better to keep a spare - you never know when an extra nipple might come in handy...

I'll see this thread again in 2023 then.