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MG MGB Technical - Sealed Axle bearings

Its funny now that I have the MG in the garage up in the air, I keep coming up with more things to do to it.

I've detected a little play (up and down) in one of the rear wheels and my hunch is a bad wheel bearing, since the hub appears to be on pretty good. Its a pretty insignificant amount of movement but since I'm going to have to pull the axle to do my thrust washers I figured why not do the bearings as well.

Does anyone know of a sealed bearing that will work for this application in place of the open one that is commonly used?

-Bill
Bill Mertz

I would not put a sealed bearing in the rear axle. They are well lubricated with the rear end gear lube which will wash the grease out of them eventually.
John H

I've seen other rearends that use sealed axle bearings and they seem to work great, but I'm no engineer. So are the non-sealed type bearings made of a different material that works better with straight gear oil, not grease?
-Bill
Bill Mertz

I have often used sealed bearings in the rear axles of older MG Models to try to keep the oil from finding it's way out onto the brakes. The oil must then pass through three seals and in a pre-war MG that I owned for many years, the oil still found it's way out through the sealed bearing but the bearing remained as good as new. In fact, I use sealed bearings where ever there is an external seal next to it Owen
Owen McNeill

Be carefull that you get the right wheel bearing with or without seals, years back we built a V-8 3.07 rear with NEW MOSS axel bearings & there was 1 extra ball & in short order BOTH were replaced with R.H.P/ O.E. bearing $12-$14jap junk bearing to $40 RHP.
Glenn Towery

With the number of MGBs and the number of miles they have done without leakage or other problems I would *never* contemplate changing the type of bearing as opposed to replacing with the original type. Are you certain sure the hub is on the half-shaft properly and it is the half-shaft that is moving up and down relative to the casing? There have been a couple of cases recently where the hubs haven't been on tight, but the cause of that has never been explained. Normally when the bearings are knackered they make a rhythmic rumbling that changes with speed but not acceleration/decelleration. It isn't a trivial task driving the old bearing off the shaft and a new one on. Make *sure* when replacing the bearing that the spacer between the bearing inner and the half-shaft shoulder is refitted, and the correct way round - the convex side faces the shoulder.
Paul Hunt

I'll recheck, but I'm pretty sure the hub is on properly. I haven't touched it in about 5 years and the problem just cropped up.
On the bearings I no common sense says "why change a good thing". But a local MG guru actually gave me the idea, and then I started thinking, "why not try it out, thats how things progress", if the dimensions and specs are the same it seems that it should work fine. If its a total failure I can report back and tell people not to do it.

Fortunately I have access to a press and numerous special axle bearing tools so the change over shouldn't be too bad.

-Bill
Bill Mertz

This thread was discussed between 05/06/2008 and 06/06/2008

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