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MG MGA - Oil leak from bellhousing - update

G'day Gents,

Some of you may recall a thread I started a while back regarding an excessive amount of oil which suddenly started emanating from the bellhousing drain hole of my 1600 (just 1,200 miles after a nut and bolt engine/gearbox rebuild).

After performing a number of tests I am now convinced that the oil is coming from the front gearbox cover, presumably past the input shaft oil seal. This would suggest that the cover was not suitably centralised on the input shaft, although I am at a loss why the leak took 1,200 miles to develop.

I am now preparing myself for the unenviable task of pulling the engine, but before I do is there anything else members would recommend that I can do? For example, is it possible that the gearbox breather could be have become blocked, causing excessive pressure inside the gearbox? Is there anything I can add to the gearbox to slow down the leak (I am using Castrol GTX2 20w-40w engine oil)?

Cheers guys

Steven
Steve

A plugged gearbox breather could eaisly cause oil to be blown past the seals. You could run a straight 50, 60, or 70 wt oil to help slow it down. If all else fails a small amount of transmission sealer that swells the seals could buy you some time. When the trans was reassembled did anyone check the input shaft for wear at the point the seal runs on the shaft?
John H

Hi Steve. This is probably a dumb question, but did you lubricate the front seal with motor oil before installation? If not, the seal would likely be subjected to premature wear, which could cause leakage. Cheers, Glenn
Glenn

If you don't get the shims right for the front bearing it can hold the gasket joint open and cause a leak.
Barney Gaylord

Before jumping to the conclusion that it is the front cover of the gearbox that is leaking I would advise that you change the gearbox oil to something like Duckhams 20/50 which is green and has a distinctive smell. This will allow you to trace the leak positively.
Iain MacKintosh

Is the there a similar product to Duckhams (green oil) sold in the States?
Thomas Koch

Thanks guys, I definitely want to explore all options before going the engine-out route.

Does anyone in Australia out there know where you can purchase Duckhams oil? I've tried several sources but to no avail. As you say, this would be the definitive test.

Also are there any tricks / techniques to remove the gearbox breather in situ? I've managed to get one finger on the bugger from underneath but there's not much room to do anything else.

Cheers

Steven
Steven

This thread was discussed between 15/05/2006 and 22/05/2006

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