MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Rear axle bearing seals and o rings

I need to replace the seal, o rings, and gaskets on my rear axle.

Can someone confirm to remove the large nut i will need a 1 7/8 socket and a puller to get the bearing out

The axle is off the car at the moment but I assume the job will be easier with it back on the car? I can’t see how I can secure the axle whilst trying to undo those nuts.

Is it worth repacking the bearings with sealed ones, has anyone done this?
C MADGE

Another thread on this lower down the main page, just done mine and did not need a bearing puller they just tapped out .
mark heyworth

The hubs will often just pull off by hand. If not, you can turn the halfshaft round and use two nuts to pull it off.

The left hand nut is a left hand thread.

It can be difficult to undo the nuts with the axle off the car, but if they have been removed before, they may not be all that tight - particularly if Graeme has tightened them LOL.
Dave O'Neill 2

I'm doing the same - removed the hubs last night, refitting over the weekend with sealed bearings.
I don't have a 1 7/8 socket, I believe a 47mm one works just as well , but I didn't have one of them either - or a 3/4 breaker bar, then there's the issue of grinding the socket to remove the rounded end for better connection - it was all getting a bit too much.
I tried a newish wrench, but it kept slipping off, so I bolted a strip of steel over the top of the wrench between two wheel studs, couldn't shift the nut. placed the handle off the trolley jack over the end of the wrench - the jaws opened up as the wrench bent. Dug deep in the tool box and found my dads old wrench - made from proper steel - bolted this into place under my retainer and the nuts came undone with no further trouble. I guess you could reverse the drum and use this to clamp the wrench as an alternative.
S G Macfarlane

The gasket thickness is critical for the correct clamping of the bearing in the hub. If it is too thick it will result in damaged hubs and broken half shafts.

Any thicker than thin card (0.4mm) is not suitable.

Cheers,
Malc.
Malcolm Le Chevalier

Yes, a 1 7/8" socket and ideally a 6-sided one, as the hub nut has no hexagon peaks for a 12-sided socket to engage with.

As above, you do not normally need a puller to get the hub off.

With regards to using a sealed bearing, there has been lots of discussion, with I think 2 conclusions:

* If you do, use a single seal bearing only, so a 6207 RS, not 6207 2RS

* Fit the bearing with the seal facing the standard lip seal

The side of the bearing facing away from the lip seal, and into the hub needs to be 'open', so that it is lubricated by the axle oil.

The torque setting for the hub nut has been the subject of even more discussion, as there is no published figure for it. I use 90 lb.ft., but I am sure there will be other views!


Richard
Richard Wale

the advantage of fitting a sealed bearing is due to the fact that the oil seal has probably worn the axle casing so it leaks a bit. I have seen people on here worried about lubrication of sealed bearings, show me a modern that does not use sealed wheel bearings,so I have no worries about them. there is a lot on the Morris Minor forums about rear bearings and stopping leaks its well worth looking it up.

Mike
M J Pearson

I fitted sealed bearings, but with the inner side seal removed which seems to work just fine. You can also buy bearings of different quality specifications to match the type of load, speed etc situation. The "Simply Bearings' website has some useful background information on this.
GuyW

Theres a good video on u tube of a rear hub strip and rebuild.
I needed a hub puller to get the hubs off. I used a suitable socket to drive out the old seal and bearing. The old bearing can be used to drive in the new one. On the old seals the inner part that should be soft rubber had turned brittle and hard - no wonder they leaked.Careful you dont damage the new bearing when you turn up the tab on the lockwasher.

S G Macfarlane

Thanks for the replies. I got the axle back on the car today and ordered a socket, so that’s next week’s job.

The pinion seal appears to be leaking too, so another job. Hopefully straightforward.........?
C MADGE

More straightforward with the axle off the car, unfortunately.

The pinion nut is torqued to 140 lb/ft, so can take some shifting. It’s a good idea to mark the relative position of the nut and the pinion before undoing the nut, so you can tighten to the same position.

An open-ended spanner can be used to prise the old seal out.
Dave O'Neill 2

140 lbft is hefty tight! The problem is holding the diff and preventing rotation. Bolt a long steady on to the pinion. As your retighten it you should measure the torque required to turn the assembly as it "preloads". Not a job to tackle on the car.
Graeme Williams

Fair enough, slightly annoying as I have just put the axle back on the car. I’ll take it off to do the pinion seal.

Today I did the right hand side seal, o ring, gasket, and new bearing today. A piece cake compared to fitting the new slave brake cylinder with those c clips. Got it fitted eventually.
C MADGE

And a pic, err just because.

C MADGE

And then I started the left hand side, like a lot of the PO repairs on this car this was done by a hammer :(

C MADGE

As previously mentioned, the LH side is a LH thread. Some people don’t realise that and try to tighten the nut instead of loosening it.
Dave O'Neill 2

Thanks Dave, I cleaned up the nut and got it off with the socket.
I don’t think I can bring myself to put it back on, I need to get a new one.
C MADGE

I think if you tidy it up, it will probably be better than a modern replacement.
Dave O'Neill 2

When I did a pinion seal I made up a long flat steel bar shaped to bolt to the coupling (about 3feet long) to stop it rotating when I had it in a bench vice.

I think it should work O.k with the diff still in the car - at least it is held stationary ! the reaction end could bear on the ground.

Colin ? if you want to borrow the bar I'm only down the road.

R.
richard b

The first time I replaced a pinion seal (diff in car) I had an assistant standing on the brake pedal - the car was on ramps.

Now, when replacing pinion seals, I normally do it with the diff out of the car and I have a similarly shaped bar to Richard. Mine is made from a five foot long piece of angle iron. The only reason for using a bar that long is that I didn't fancy cutting it shorter.
Dave O'Neill 2

Richard thanks for the offer of the bar, I have bought some angled bar from b&q which should do the trick. But if not i’ll take up your offer,thanks.


C MADGE

The 140 figure is only nominal, the torque on the pinion nut sets the preload on the bearings. Too tight and you will crush the collapsible sleeve, and the preload will be too much, not enough torque, and the preload will be not enough.
Better to mark the nut, and retighten to that mark.

That's assuming the diff has not been modified in the past,to replace the sleeve with a non collapsible item.

Dave
Dave Barrow

This thread was discussed between 14/06/2018 and 23/06/2018

MG Midget and Sprite Technical index

This thread is from the archives. Join the live MG Midget and Sprite Technical BBS now