2007 Q7 3.0 TDi 4L 6 speed transmission oil change.

[GrimleyQ7]

Hello all.

New member looking for advice regarding my Q7 and changing the transmission fluid.

I have purchased the fluid (Dexron 3 ATF), the filter kit with gasket, the fluid pump and adaptor nozzles.

I'm a pretty competent DIY'er and this weekend changed the engine oil & filter, diffs and transfer case oils, serpentine belt & tensioner, cabin, air and fuel filters.

All done on the driveway without a ramp. Suspension on lift and a lot of writhing around on the floor.

However, I came to do the transmission fluid and hit a stumbling block...

The fill plug in the 6 speed 'box looks to need some huge allen key to remove it, or some Audi specialist tool.

I'm guessing it's about 20-25mm without measuring.

Does anyone know where I can find such a tool?  As I don't want to end up stripping it out and causing a whole world of pain.

I can't seem to find any info on the tool needed to remove the fill plug despite hours of searching the internet.

All advice is gratefully accepted.

Thanks & regards.

Chris.

[Steve Q]

Well done for doing all that servicing work yourself. This YouTube video might help to show you how to do it etc. 

 

[GrimleyQ7]

Thanks for the reply Steve.

I have watched that video already and the drain / fill system on that 2011 model is different to my 2007.

My transmission oil pan has separate plugs for drain and fill. Drain on the nearside and fill on the offside.

The fill plug being a large allen head plug and the drain being a 5mm allen head similar to the video.

Also, the filter is different to the video too.

The principal however is the same.

Thanks.

Chris.

[Magnet]

Hello Chris,

Excuse me appearing to be patronising, but well done you by making sure you can undo the filler plug before undoing the drain plug. Many before you haven’t with differentials and gearboxes, only to find they can’t refill them! 
Anyway, back to your question about the availability of a large Alen head socket. Laser Tools used to do a variety of largish ones  ( big enough for you?) as a set, so worth looking to them. Have you done an eBay search for the size you want? Have you tried Halfords? If all else fails - and I doubt if it will - you could take an accurate measurement, and search out a steel stockholder and buy a short length of the correct size hexagonal bar. 
Perhaps you could let us know how you get on.

Kind regards,

Gareth. 

[GrimleyQ7]

Cheers Gareth.

A lesson I learned many years ago with an old Range Rover.

Anyhoo, I have found a picture of the gearbox sump on my Q7 as as you can see, large allen head fill plug, small torx (on this photo) drain plug.

I know I'm just going to have to measure it and then track down some big Allen keys.

I think it's an M30 thread so it's possible it could be around a 20mm key needed.

 

[Magnet]

Thanks Chris,

Is it difficult to put an internal calliper in this plug and get a good measurement? 
Allen key? I’d be surprised if someone ( apart from Audi) doesn’t supply the correct socket for this - probably common to many marques. 
I’d be giving this a good coat of Googling.

Kind regards, 

Gareth. 

[Lukebris]

Hello Chris,

Did you find out the size of the Allen key? 
I ran into the same problem.

Regards

Luke

[GrimleyQ7]

Hi Luke.

Yes I did and I managed to get the change done without any major issues.

The fill plug needs a 17mm hex bit socket or big allen key.

I had to use a breaker bar to get mine undone as it felt like it was welded in!!

The other awkward bit is the bolts on the sump pan that are above the cross member.

These need a UJ on a rachet or one of those wobbly type rachet extensions.

I replaced all the sump bolts and wavy washers with stainless steel. I also had new drain & fill plugs with their respective o-rings and washers.

Hope that helps.

Cheers.

Chris.

[dillon]

After you got it out did you still need to use one of those special adapter to refill the transmission?

[GrimleyQ7]

Hi Dillon

Yes I did.  I purchased a pressure fill system off eBay.

https://www.ebay.co.uk/itm/392977805026?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Q8qYiOZhQS6&sssrc=4429486&ssuid=7fjf4C9SSKa&var=&widget_ver=artemis&media=COPY

Chris.