leaking diff

[JF008]

One of the output flange seem to be leaking on my 3.25 lsd, enough to see the drips on the ground. What repair kit do I need to get? I don't know the name of the parts or what the parts are, I will get it done in a garage but I would like to source the parts myself from the dealer.


Any advice appreciated!

JF

[Brianmoooore]

http://2009.bmwfans.info/parts/catalog/ ... on_gasket/

#3 is the seal, and is easy to change, once the driveshaft is disconnected and out of the way.
The output flange and dust cover (parts #1 and 2), just prise out (held by a snap ring), allowing full access to the seal.

[JF008]

Thanks Brian!

[knob]

Hi Guys,
Sorry to tag on to this post but I removed my Is lsd at the weekend, as part of overhauling all the back end stuff, and noticed that both the dust seals on the output flanges have rotted away and I was unsure of how to replace these. The seals seem ok, no leaks but will change them anyway after reading Brian's comment on how easy this is to do. Cheers for that Brian.
My main problem is the front seal, which is leaking and I dont know how best to fix this. Checked the Wiki and it does not cover undoing the big nut and removing this flange. Anyone know how much torque is on this nut and how best to loosen it?
Is it a straightforward job of removing the nut and just pulling off the flange to get at the seal and dust cover? or are there any complications to this simple approach that I should be aware off?
Thanks for any help with this.
Cheers
Jim

[Brianmoooore]

Yes, there are complications with changing the pinion oil seal! Most don't ask until they've already removed the nut, and by then it's too late.
The nut isn't tightened to a specific torque - it has a collapsible sleeve behind it, that crushes shorter as the nut is tightened, to set the mesh between the crown wheel and pinion gears.
Mark the exact position of the nut on the shaft it screws onto, then unscrew it, counting the exact number of turns before it comes off. Pull off the drive flange, change the seal, then reassemble, using the same nut and flange, and tighten the nut to exactly where it exactly where it originally was.

[knob]

Thanks Brian, I'm glad i asked now. Will I have to replace the collapsible sleeve or will that be OK to re use?
There is a yellow paint mark on the nut and shaft so perhaps it has been removed and reset once before.

[Brianmoooore]

Sleeve is reused and not disturbed. Ideally, it would be, along with the pinion bearing, but that gets you into a much more involved job, involving things like engineer's blue and specialist knowledge.

[knob]

Cheers Brian,
Sound advice. I think if I can manage to repalce all 3 seals and dust covers, then I will be happy with that.
Thanks again
Jim