Gearbox End Cap Leak

[Morrisey]

Hi all,
I hit middle age & decide to have my first foray into VW, buying a '08 GTI.
1 week in (regretting I didn't get one years ago) I find an oil leak
I clean down the gearbox case, run a few more miles to confirm it's coming from the Gearbox input shaft end cap.
Now this would be an easy fix, replacing with a cheap £10 cover from within the nearside wheel arch. However, I can clearly see damage to this cap, with what looks like impacts from within the box.
Is this possible bearing failure, where the bearing cage/balls have been forced outwards?
This is going to be checked out next Monday under warranty by the dealer, but I am concerned they will just replace the end cap for new and ignore the possible cause.
I don't want a ticking time bomb where one day (out of warranty in 2 weeks) the fragments decide to strip my gears!
Has anybody witnessed this before?

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[Octoparrot]

There have been some cases of the bearings allowing a shaft in the box to move causing damage to the end cap, however it is also possible for the cap to corrode causing the leak that you have. The damage you see could just be rust bubbling under the coating, Andrew Chapple had this exact problem on his edition 30 which he documented in the now defunct VW Driver magazine, fearing a bearing problem it turned out replacing the cap solved the problem, hopefully yours will be the same. Keep us posted.

[Morrisey]

Cheers Octoparrot, this is looking more promising.
More confident in using the car over the weekend now, before judgement next week.
Can anyone confirm that the part number 02M301211B is solely made of plastic or is it steel with a plastic coating (to help seal the hole)?

Found another example of somebody else's leaking cap, again showing severe bubbling to one side.

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[Morrisey]

Just found this post
https://www.mk5golfgti.co.uk/forum/index.php?topic=106577.msg1056663.msg#1056663
Same issue, Chris just changed the cap.

Also took a magnet to this, it sticks to every part of the cap face except 8-10mm diameter in the centre -confirming it could rust everywhere else!  All photos also indicate this.

Replacement should be an easy fix

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[ChrisGT]

Yep,

That's from my build thread. It was just corrosion on the cap, replacing it should be all that's required. 

Chris

[Morrisey]

Cheers Chris (the Mk5 expert)
Hope every fix is this simple

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[MPS]

Hope every fix is this simple

 

[ChrisGT]

 

Let us know how you get on 

Chris

[Morrisey]

Warranty job complete (easiest you'll ever find on any forum).
Old cap off, new on.

A steel disc is housed within the plastic cover, so will always be prone to rust if a pinhole damages the plastic.

...just hope the oil has been topped up!

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[ChrisGT]

Glad you got it all sorted,

Chris

[pudding]

Did you check the gearshaft end float whilst you were in there?

[Morrisey]

As it was under warranty, I didn't do it myself so couldn't check.

-Didn't the younger mk5s have a shim inserted from factory anyway? (sure I read that somewhere, sometime, or just made it up!)

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[pudding]

Almost right.....it was the mid 2007 onwards that got the shim from the factory.

If you don't 1st/2nd gear gear selecting issues (if it's a manual) and/or high rpm miss shifts then the end float is probably OK.