A4 B8 Gearbox oil leak?

[Mr Zap]

There is what looks like oil leaking from around the gearbox area, well I think it's from the gearbox, but even up on the lift I can't see it actually doing it so I can't see exactly where it's coming from. The fluid is clean (so not from the engine) it's not diesel and it's not hydraulic fliud either so it must be gearbox, but it's not red either. Is it possible that the gearbox oil is clear? Also, how can I find out exactly what gearbox it has, can someone look it up based on the VIN? It looks like a CVT unit but again I'm not sure. Any help appreciated. Thanks.

[VAG-Abound]

Do you have a printed sticker in the service book, or somewhere a bit hidden in the boot? That should give engine and gearbox code.

[Crasher]

What is the VIN. Yes, CVT fluid is very clear.

[Mr Zap]

Ok I found the sticker in the book, the gearbox code is LLA which I believe makes it a multitronic CVT box. I've also been told it's not uncommon for these boxes to "weep" oil, is this true? There doesn't seem to be a huge amount coming out, judging from the contents of the drip tray I threw under it, but it's only just started doing this and either way the majority of the escaping oil appears to be drivers side, although it is definitely not coming from the output drive shaft. So, assuming the box is the source, where's the oil most likely to be escaping from, and are they worth getting seen to?

[Crasher]

Yes that is an 0AW series CVT box, you need to know if it is "axle oil" or " ATF" CVT fluid.

[Mr Zap]

I do? Ok, how do I tell, and please forgive my ignorance but what difference will that make (apart from knowing what to use to top it up with)?

[Crasher]

There are two oils in the box, one for the differential and the other for the CVT system, mixing these is disastrous and over filling either also a disaster. The level of the gear oil is easy to check with the car on a lift on a level surface but the CVT fluid has to be checked with the engine running and the fluid between 30 and 40 degrees C. The two fluids feel and smell quite different so a grease monkey with experienced olfactory recognition skills can tell which is which.

[Mr Zap]

So, quick update to round this job off: The leak was from one of the two gearbox oil cooler pipes that go over the top of the box, fractured where the small securing bracket was (again on top of the box). The guy who did the job for us said it was because someone had previously had the DPF box out but during the lengthy job that that was had neglected to refit the 10mm bolt that secures those same pipes towards the front of the engine, hence allowing those pipes to waggle about and eventually fracture at the rearward bracket.

Thankfully it seems the box didn't actually lose that much oil, and so far is running again fine. I realise that there is a possibility that the loss of oil may lead to problems that won't necesssarily manifest themselves yet, but I think we've bought ourselves a bit more time with the car and we are now at least half-prepared for whatever happens next.