Gearbox Leak

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clarko74
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Post Wed Aug 28, 2019 11:31 am

Morning all,

My Getrag 260 gearbox is currently off and it's clear that there is a leak from the Rear of the gearbox somewhere:
20190828_091537.jpg
As far as I'm aware the only places that will leak around here are the shifter linkage seal and the output shaft seal. Given how high up the oil is I suspect it is the linkage seal, but then again there is a lot of oil all around the output shaft, what do you think? From my research it seems the shaft seal replacement is quite simple but the output shaft seal is more tricky, how big a job is this?
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paultv
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Post Wed Aug 28, 2019 12:42 pm

Is there oil towards the front of the box or all at the back ?

As there's oil directly under the shift seal, in my experience it is leaking, and the spread of oil over the back also suggests a rear main seal failure as well.

As the box is off the car I'd do all the main seals, if you suspect any of them at all.

Is the vent at the top of the box free ? It should losely move up and down if you pull on it - if not it could be blocked which causes pressure build up in the
box which can push oil past the seals.

To remove the old seal, remove the lockplate by bending the tabs then pulling the plate off undo the big bolt, you'll need an impact driver and a 30mm thin walled socket then pull the yoke off - you may well need a puller to get it off the shaft.

The seal is directly behind this and relatively easy to get out with a seal remover or screwdriver - don't bugger up the case housing when you do this!!

Paul :-)
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Brianmoooore
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Post Wed Aug 28, 2019 1:53 pm

Check that it's not coming from the vent right t the top of the rear of the box, but the chances are that it' s just the linkage seal that's the problem. This can leak a surprising amount of oil, which runs down and around the output shaft, giving the impression that the seal there is leaking as well.
clarko74
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Post Thu Aug 29, 2019 9:23 am

The oil is just to the rear of the box, the front is clean and dry. I will check out the vent to see if I can move it and if there is oil coming from it.

I think while it's out I will just change both.

Cheers for the advice.
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paultv
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Post Thu Aug 29, 2019 1:17 pm

The vent just needs to move up and down easily. It doesn't spit oil but causes a pressure build up in the box if blocked which can cause leaks at the seals

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
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Brianmoooore
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Post Thu Aug 29, 2019 1:56 pm

clarko74 wrote:
Thu Aug 29, 2019 9:23 am
The oil is just to the rear of the box, the front is clean and dry. I will check out the vent to see if I can move it and if there is oil coming from it.

I think while it's out I will just change both.

Cheers for the advice.
If you insist on changing the output seal, don't forget to use sealant on the splines, or you will get a leak where there wasn't one before.