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MG TD TF 1500 - Rear Axle Oil Leak

500 miles ago I had a leak of oil on the outside of the rear wheel, ok I thought, probably a brake cylinder, but the leak was coming from the half shaft oil seal, I duly replaced it.
Recently I noticed a leak of oil on the outside of the rear wheel, ok I thought, this time it must be a brake cylinder but the leak seems to be coming from the half shaft oil seal again!
The half shaft itself has an end float of 1/8'' is this usual and why should the seal still be leaking?
What is a bit weird is the leak looks like the rear axle oil and reacted in some way with the bearing grease.
Any ideas?


Cliff Harvey

Good day Cliff. The wheel bearing should not have any grease. The bearing is lubricated by the diff oil. Check the surface that the seal rides on (the spacer)this surface needs to be perfectly smooth no scratches or burrs. Also when the new seal is pushed on it needs to be lubricated with the diff oil, otherwise the lip of the seal will burn and be ruined.
R Taras

Thanks for the idea, I've checked the collar that the seal rides on and it is not perfect, it's got to be worth replacing, although the seal looks ok I'll change it as a matter of course.
Cliff Harvey

Cliff: I had a similar leak of differential oil into a rear wheel with the slightest wheel wobble... Turned out the castle nut on the half axle was not tight enough. Advice on the board ranged from 60 to 150 ft/lbs, before you pin it. I went with the latter. All good now and no real flow, just enough for lubrication. This may be old news to you but I thought it worth mentioning as a possible cause. Happy motoring on Dartmoor !
Here's my Dartmoor motoring shot...
--Peter


Peter Pope

Great shot Peter, I've seen this dog driving over the Moors many times, they train them really well up there. (For those wondering what Dartmoor has to do with this thread? ... nothing really, I think Peter was inspired by my 'Nice Surprise' thread).
Cliff Harvey

Cliff,
The halfshaft should have NO end float, the bearing is a tight press fit on the shaft. This needs urgent attention, the axle nut should be at 150 lbs/ft. Any slackness will quickly wreck your drum and they are very hard to come by.
Bearing is RMS10 or MJ 1 1/4 RS.
Possibly a thinner bearing has been fitted by mistake.
Again, it is urgent!
Ray TF 2884
Ray Lee

Just remembered that if the bearing spacer (part number 32 in WSM Pic H2) is left out the axle nut will bottom before the drum is clamped.
Ray
Ray Lee

Cliff,

The other thing you could do is replace the bearing with a sealed one. In that case you don't need an oil seal.
I did this a few years ago, since then, no leaks.

John

52 TD
J Scragg

Cliff, Since my TD has an MGA diff in it I do not know if the originals have a vent. If they do you should check the vent to see if it is clear. The oil seeping from your bearing looks to be contaminated with water... most likely condensation build up from not being able to vent off the moisture. If a vent is not venting it can also allow the diff to build pressure that will help push fluid out of the diff.
... CR
C.R. Tyrell

Thanks CR but I've checked the vents and they are clear, there's no water present just oil going down through the grease.
I've now removed the back plate and bearing hub. The internal bearing spacer is in place.
The bearing is marked RMS10, so is correct.
The half shaft is not tight press fit on the half shaft in so far as I can manage to slide it on and off by hand, however it is a tight press fit in to the axle hub.
Before I dismantled the back plate, I replaced the split collar and brake drum and tightened the nut, when I do this the end float is pulled up so is this an issue?



Cliff Harvey

Close up of oil seal, the lip looks a little flattened, my replacement is on its way.


Cliff Harvey

The other side.


Cliff Harvey

there is a slightly smaller internal diameter seal avaliable..I used it last time. Have a look in the archives. Can't remember the specs :-)

Dave
D Moore

Hi Cliff,
If tightening up the axle nut took out the free play you should check the brake drum.
I worked on one TD that because it was loose it had worn the taper in the drum.When tightened up the drum fouled the backplate and the shoes bound on the inside of the drum.
Ray TF 2884
Ray Lee

It looks like the half shaft is able to be pulled out of the bearing by hand. While this is probably not a cause for your leak problem it's not correct. The bearing is supposed to be a press fit on the half shaft.Perhaps the bearing is cracked?
Dave
Dave Clark Arizona

not sure on those marks on the inner bearing and half shaft.

But anyway, do you have a lip seal fitted to the inside of the bearing carrier/end of axle tube? as this does not seem right? it would allow oil to sit in the bearing carrier.

as long as the bearing is not worn then any tendency for the inner race to spin should be taken up by the collar tightening on the inner, then spacer, then half shaft.

mog

This thread was discussed between 19/04/2015 and 27/04/2015

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