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MG MGB Technical - Diff Noise

I recently acquired a 'ticking' noise from the rear end. This is not a 'clunk' on acceleration or decceleration but more like a bearing tick. I thought at first it was wheel bearings but it is comming from the diff.

I have ordered new thrust washers and have read the archives for details on the job, but I seem to get only descriptions of the tube type axle. Mine is a '67 Banjo type. Apart from the fact that I have to remove the whole diff centre instead of the rear plate, is there any difference between replacing the washers on the two types.

Also, as it is possible that it is the inner bearings, what sort of job am I up against to replace those?

Thanks

Tony
Tony Oliver

There are several pages of instructions in the Workshop Manual involvcing special tools, it's not covered at all in Haynes, so a major job. For just a tick, it may not be worth it. Oil level OK, I presume.
Paul Hunt

I have a noise from the rear,. when coasting I can hear, a rub rub sound,. MG shop looked at this,. it is not a bearing,. but,. a sound from somewhere deep in the diff,. they said it is not worth the trouble and expense to tackle this,.
I shall get used to this,. hardly notice able,.
diff has full oil level,.
mike hoaglan

If it's bearings you ought to change them especially the pinion bearing. If it goes you can get severe damage. Do them all at the same time. Bearings shouldn't be a problem to source.

This can be done by an experienced differential shop without having the special tools...it take's longer w/o the tools and isn't as precise.

The key is getting the gear mesh right. They have to shim things and check the mesh with prussian blue. Otherwise you'll get noise and undue wear on irreplaceable parts. With an old crown and pinion things won't be perfect. These axles are noisy so don't expect silence.

You can take the axle to the shop yourself and save some money. Thing is if it's noisy they'll have to reshim so it may have to come out again.

I've done this myself on an Mustang axle and it was successful. The pinion and differential carrier bearings were all pitted and made awful noise. Much quieter after the redo.
Robert McCoy

About 15-20 years ago I had a strange humming sound coming from my differencial. It wasn't bad but was annoying. Next time in the shop I had them drain it, wipe it out and replace the lubricant. Its been fine ever since and pretty cheap to do! Bob
Bob Ekstrand

HA! Saw the bit in the manual about replacing bearings. Looks like it is beyond my capabilities.

Diff is in pieces and I can't really find any faults. New thrust washers going in regardless but the carrier bearings seem pretty smooth.

The ticking noise is very evident when coasting so perhaps it is a hub bearing and the noise just sounds like it is in the diff.

I'll report back when I have got it all together again.

Tony
Tony Oliver

Mike - as an opposite comment I'd say leave well alone. It just isn't worth the major work, which could do more harm than good.

I had a diff oil leak that only happened when running, barely a spot on the garage floor so I didn't really notice it, until it ran out of oil a dozen miles from home and started grinding. Carried on as gently as I could, replaced the gasket and refilled with oil, and it carried on like that for many years and tens of thousands of miles until I replaced it for other reasons. If anything it was gradually getting quieter over time - or I was getting deafer!
Paul Hunt

This thread was discussed between 26/02/2009 and 27/02/2009

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