Rear wheel oil issue

[moggiethouable]

I was checking the rear brakes, when I noticed oil stains on the outside of the brake drums, on removing the drum I found no oil inside, but removed the philips screw holding the hub on to find a trickle of oil.
The manual doesnt tell me too much, so, should I be replacing an o ring and gasket or is it more complex than that please?

[Trickydicky]

It could simply be the O ring and the gasket. If you need to remove the half shaft make sure your not parked too close to a wall to withdraw it.

[simmitc]

Where on the outside of the drum is the stain? Oil can come from numerous places such as the dampers, a hole in the axle casing, blown through from the engine (unlikely, but possible) as well as from the hub. Is it just an old stain from when somebody dropped an oil can, or is it fresh evidence of a leak? Which sort/year of axle have you got, as that could make a difference to advice.

[bmcecosse]

It may be a sign that the bearing is developing a bit of wear. If you jack up and grab the wheel .. can you feel any 'play'?

[moggiethouable]

Ive not checked for play yet.
I will do though.
The oil was apparent at the centre of the brake drum (inside) just a light smear for the moment.
When I removed the hub there was a dribble of said oil appeared.
Is there a gasket that goes between the hub and its backing the philips screw attaches to?
Or more to the point, should the hub oil seal stop any oil getting as far as the back of the hub?
If there is play on the bearing are you suggesting the axle shaft will wobble in its seal and let oil through BMC?
The model by the way is a 65 saloon.

[bmcecosse]

Yes - oil could escape that way.

[moggiethouable]

thanks

[simmitc]

I noticed oil stains on the outside of the brake drums, on removing the drum I found no oil inside

The oil was apparent at the centre of the brake drum (inside)

Sorry, am I missing something: The two statements appear to be mutually exclusive. The most usual cause of a leak is undoubtedly the hub seals, but it would appear inside the drum on the mating surface where it touches the half shaft. Half shaft to hub is the one area where I am in favour of sealant as well as gaskget. Also, when fitting the half shaft, nip it up tight with some washers and reversed wheel nuts on the studs before tightening the retaining screw - this ensures that it is even and fully home.

[moggiethouable]

I noticed oil stains on the outside of the brake drums, on removing the drum I found no oil inside

The oil was apparent at the centre of the brake drum (inside)

Sorry, am I missing something: The two statements appear to be mutually exclusive. The most usual cause of a leak is undoubtedly the hub seals, but it would appear inside the drum on the mating surface where it touches the half shaft. Half shaft to hub is the one area where I am in favour of sealant as well as gaskget. Also, when fitting the half shaft, nip it up tight with some washers and reversed wheel nuts on the studs before tightening the retaining screw - this ensures that it is even and fully home.

Yes quite right, I should have said I noticed staining on the outer of the drum, which led me to remove the drum and found a light smearing on the inside face centre.
I hope to get some face to face info when I visit Tom Roy this week,thats always an experience, usually educational and always thoroughly entertaining.
I assume that if the inner seal, (wheel side of the bearing) is doing its job I shouldnt see oil behind the hub when I take it off?
Is that correct?

[bmcecosse]

Sure it's not just oil/grease that has been applied to the wheel studs to make the nuts run up nice and easily? The half shaft end flange is trapped up tight to the hub face - with a thin paper gasket and an O ring between. Initially held in place by a single screw - then the drum is fitted over and another two screws are fitted ( ) and then the wheel is fitted - and the 4 wheel nuts are torqued up. Effectively then the wheel studs/nuts hold it all together and hard to see how any oil can escape. If the hub rear seal is worn/gone hard and/or there is a little wear in the bearing - then some oil can escape there - but will be seen on the backplate and perhaps the outer rim of the drum.

[Ufudu]

Roy, can you please confirm, should you use both paper gasket and O ring?

I did, but don't understand why one metal face needs an O ring and the other does not?

[moggiethouable]

Sure it's not just oil/grease that has been applied to the wheel studs to make the nuts run up nice and easily? The half shaft end flange is trapped up tight to the hub face - with a thin paper gasket and an O ring between. Initially held in place by a single screw - then the drum is fitted over and another two screws are fitted ( ) and then the wheel is fitted - and the 4 wheel nuts are torqued up. Effectively then the wheel studs/nuts hold it all together and hard to see how any oil can escape. If the hub rear seal is worn/gone hard and/or there is a little wear in the bearing - then some oil can escape there - but will be seen on the backplate and perhaps the outer rim of the drum.

Ok, as its no great shakes I will fit a new gasket and o ring as a matter of form, given the opportunity at the weekend I will if necessary take a photo or two.
n.b. it was oil stains on the outer rim of the drum that set me off on this tangent in the first place.
Thanks for the info.
Always appreciated.

[bmcecosse]

The gasket gives the necessary 4 thou spacing effect I think - to ensure the bearing outer is firmly gripped. The O ring is obviously 'squashable' - and just ensures the seal.....

[kennatt]

you don't say what car you have but be aware some of the early cars didn;t have the o ring,no groove in the half shaft flange.My ser11 always leaks if I take a wheel off,I now make sure that the side I'm working on is high enough to let the oil run down to the otherside before taking the wheel off. Never leaks into the drum when the wheel is on,but no O ring on mine,maybe thats why it was modified on later cars.

[bmcecosse]

Indeed - it was!

[simmitc]

The car was identified as a 1965, so should have the O-ring.

[moggiethouable]

Thanks for the info gents.
I removed the necessary today and replaced the o rings and gaskets.
The old gaskets were like a good saturday night out, well oiled and neither use nor ornament.
It does explain why there was oil reaching the brake drum.
I would comment that the hub assembly looks not a lot like the blow up in the Morris manual.
A bit late to complain I imagine.
No play on the bearings BMC, so thats good.
I would say it seems a nice simple design, perfect for fitters like me.
Sorted now anyway, so thanks again.