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rear diff leaking oil
Posted: Tue Oct 09, 2007 4:05 pm
by CHIEF88
Hi,
My rear diff lost a lot of oil (~1L) on a trip up the highway recently, I dried it all down and replaced the diff oil to get home; however, it still leaks (not really suprised) and seems to be leaking from under the front of the diff.
This is a picture of my diff

The area in red is covered in oil which runs down the diff as well.
In that picture my guess would be that its leaking from point A however point B has oil around it too.
My question is, is the gasket at point A the most probable cause of the leak and how hard / easy is that to replace, and what is involved?
Posted: Tue Oct 09, 2007 4:20 pm
by nayto
first of all your axle housing looks a little bit bent

but on a serious note, id be thinkin point B which is the lip seal goin into the diff, not a big job to replace if the seal surface looks ok. Although how long did it take to loose all the oil? must be a good leak.......
Posted: Tue Oct 09, 2007 4:28 pm
by CHIEF88

haha
well tbh I have no idea how long it took as i could have been leaking for quite some time. I only noticed it after a longer than normal trip up the coast when it dripped onto the driveway.
could it have had a lower boiling point from sucking in water previously and on long trip boiled and burst thru seal breaking it?
I will have to wipe it down again and try see exactly where its leaking. If it is leaking at point A is that a harder job to replace?
Posted: Tue Oct 09, 2007 9:03 pm
by johno88
It is the seal at point B. You need to remove the drive shaft. You will then see a large nut inside the yoke that is crimped onto the pinion. You need to lever the crimp out and undo the nut. You can then remove the yoke. You can then remove the seal by either using a slide hammer or just butcher it. You then need to look at the yoke - if there is pitting or groves from the seal, you can buy a "speedie sleeve" that slips over it. If it looks okay, clean it up with some sandpaper. Replace the seal and put it back together. Put a bit of oil in the sleeve before you slip the yoke in. Ensure you do the nut up the same amount of turns.
Posted: Wed Oct 10, 2007 10:24 am
by bazzle
Spray with degreaser, hose off.
Check breather is open (if original prise cap off and add a rubber hose.)
Go for a drive (check level 1st) and see where it leaks.
Bazle
Posted: Wed Oct 10, 2007 6:39 pm
by CHIEF88
Well I bought a seal for point B today $5 was pleased, although I thought it was gonna look like a gasket or something not a little shallow cup shaped thing. When I put it in I guess I'll find out if its the right thing or not.
Also did as advised and cleaned the area up and dried it. took it for a 10 min drive and no leaking :( (only had time for that couldn't drive it more)
Did i get the right seal ?

He said this was the one going btwn yoke and uni joint.
Posted: Wed Oct 10, 2007 10:41 pm
by Sic Lux
Yeah looks close enough to be a pinnion seal drop uni off and yoke few tricks to it like mark it all so yoke goes back on the same position it comes off and do bolt up only as far as it comes off other wise it'll over tension the crush washer inside the diff causing it to come out of adjustment and probbaly strip teeth
Posted: Wed Oct 10, 2007 10:44 pm
by CHIEF88
Sic Lux wrote:and do bolt up only as far as it comes off other wise it'll over tension the crush washer inside the diff causing it to come out of adjustment and probbaly strip teeth
Sounds kinda fiddly is it a very precise thing or could it be out by like 5mm of a turn and not matter ?
Posted: Wed Oct 10, 2007 10:50 pm
by Sic Lux
Yeah when you are doing it up do it till it gets tight and just turn and check and turn and check till it's spot on not that hard when your doing it
Posted: Wed Oct 10, 2007 10:51 pm
by Sic Lux
Also feel for how much back lash it has could be that the bearings are flogged out
Posted: Wed Oct 10, 2007 10:53 pm
by CHIEF88
what do you mean by backlash ? I've never done it before.
Posted: Wed Oct 10, 2007 11:08 pm
by Sic Lux
How far the yoke on the pinion turns before it wont turn no further and the back the other way till it won't turn no more to set it the diff needes to be out of the housing
Posted: Sat Oct 13, 2007 10:43 am
by CHIEF88
Ok so how do people get around the fact that the bolt thing is done up uber tight. How do mechanics even get it off?
Posted: Sat Oct 13, 2007 4:03 pm
by johno88
dont use your rachet, use the solid bar and slip a peice of water pipe over it. If that doesnt work, take note of how far it is done up now, then get the rattle gun onto it.
Posted: Sat Oct 13, 2007 5:22 pm
by CHIEF88
yep had the solid bar onto it but could only push so hard with my hands holding the bit the uni joins too. How do you lot stop that from spinning ? pop reckons they used to get steel and bolt it to either side where the uni bolts too then the steel acted as a good brace. I dont have any spare steel or anything like it
Will have to try the extra leverage and maybe jam something under it to stop it spinning.
Posted: Sat Oct 13, 2007 5:36 pm
by johno88
to try and stop yoke from spinning, put a large phillips head screw driver through one of the 4 bolt holes, so the end of the screw driver will be pointing to the back of the car, turn the big nut and the screw driver will jam againest the diff housing. then you should be able to crack it. i used a large pin punch instead of a screw driver but it should work just as well. good luck
Posted: Tue Oct 16, 2007 2:56 pm
by CHIEF88
anyone feel like coming over to my place
I'm in need of assistance can't get the rear most uni joint off to see the yoke and seal. It's stuck pretty tight. Any tips / suggestions for removing the rear uni from the diff? And yes all four bolts are removed

just seems stuck on there.
Posted: Tue Oct 16, 2007 3:07 pm
by CHIEF88
OK nvm got uni off required a bigger lever
Now I find my sockets only go to 24 I think it must be like 28 or something that I need for the bolt in the yoke.
