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MG MGA - Differential Oil Leak

The other day while servicing the rear brakes, I noticed that when I took the drum brake cover off, there was a minor drop of oil coming out from the end seal.
The oil only seemed to come out when the wheel is in a certain position, i.e. the seal must be damaged only at a certain point.
Later I found out that the cross-head screw holding the end together was loose... so I tightened it, put the drum over again and tightened the drum nuts. I knew this would be something I would need to address soon.

It has been fine for a couple of weeks, but this weekend while working on the wheels (completely re-sprayed them) I noticed this drop of oil again hanging from the bottom of the drum. Obviously I realise this is back because it can contaminate the brake linings.

So I have been looking at Barney's section on this;

My question is;

- If I change the half-shaft outer paper seal will this cure the leak alone?
- If there is oil coming out thre, does it mean the bearing seal is also shot, and need to change it too + the O-ring.
- In both cases how big is the job? and will I be able to complete the job without making a big mess?

And the bonus;
- While I am at it, and the diff. oil is drained, would it be work fixing the back lash on the differential? I seems quite pronounced on my diff.
Or is this a completely different (i.e. Huge) job?

For those who have completed this kind of job I would appreciate your insight.

Gonzalo Ramos

Bad news, today I took the brake drum off, and the is more oil leaking than I thought.
All the brake pad linings and inside of the drum are oiled! ;(
The worst thing is that it seems like the oil is coming from the bearing seal and not the half-shaft paper seal as I thought originally.
I am wondering why this would have happened suddenly now...I read something about pressure building if the vent is not open?

Well I guess I need to go for the full hub seal rebuild.
I gonna go look for an octagonal socket... : )
Let me know if any of you has a spare!

Gonzalo Ramos

Hi Gonzalo, This is quite a common issue and there have been a number of threads on this subject.
If the shaft is pitted then the seal wont!! In that case you can buy a sleeve that can be pushed onto the shaft which will create a new sealing surface. I will get round to doing that myself in the coming months.
Take a look through the archives to find some sources and the size of the correct sleeve.

Neil Purves

Indeed I found enough info. in the archives on this particular issue, so it will be this weekend's job.

I have also found a source for one of the alternative sockets locally, and probably will think of something ingenious to take the hub out.

Gonzalo Ramos

Go for the Speedie sleeve first up and decent socket (Moss is good). A sliding hammer hub puller from Harbour Freight is a good investment also ~$55. All the info to fix is on Barney's site. Also check out his page on removing diff backlash. If you go to all this trouble make sure you clean the inside of the banjo housing especially if you find the diff has started to fail.
Mike Ellsmore

This thread was discussed between 24/05/2010 and 26/05/2010

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This thread is from the archive. The Live MG MGA BBS is active now.