dzywicki

Decided to start a new thread to consolidate wisdom. I have done a lot of reading already, but could not find a good pic of where the drain/fill plug is for the front differential on an A6 quattro system.

Transfer case: https://www.audiworld.com/forums/sho....php?t=2752978
Transmission is pretty obvious: http://www.ehow.com/how_5000414_chan...i-quattro.html
Rear diff is pretty obvious

Where is the drain/fill hole on the front differential?

I put the car on ramps last night and looked around for 15 minutes and couldn't find anything that looked like a drain/fill plug.

I attached a pic of the trans. Just to verify, the upper plug is the drain and and the bigger plug on the bottom is the fill right? I have not had a car that had the fill plug on the bottom with a riser like that.


There must be something obvious I'm missing with the front differential. I do maintenance on 3 different Jeeps so I know my way around 4WD systems pretty well.

Thanks for any help!

hrc4u

If I recall right...you can see the plug if you remove passenger side wheel..

raj99

I did the change of the diff and crank case fluids less than 2 months ago.

The front diff fluid can be accessed from the passenger side of the diff and needs to be extracted out with a pump. There is no 'drain plug', you will need to pump the fluid out and then replace it the same way. This is the same for the rear diff, which also needs to be extracted. The only one which has an actual drain plug is the crank case (center) and it's pretty obvious.

I wish I'd taken pics of when I did the change. FWIW, I did not need to remove the passenger wheel liner, but then again I had a lift.

dzywicki

Awesome, thanks for the info!

I was going to use a tool like this: http://www.harborfreight.com/oil-suction-gun-95468.html
Looks pretty useful for putting the fluid back in too.

I have tried other fluid suction tools and they all seemed to suck.

raj99

sounds good, but if I recall the rear diff needs to go 'up and over' and needs to have some sort of syphon like the following plastic portion: http://www.harborfreight.com/5-gallo...ump-95068.html

so that you can pump oil over the lip, without just shooting it in and hoping that it's going in.

Also, I ended up using a friends electric extraction unit like the following which worked GREAT:

cal3thousand

I bought this one in preparation for the same job (it pushes liquids too):




Interesting that you did not have drain plugs for the front and rear diffs. Guess I will find that out soon too.

raj99

on my 4.2 there were no drain plugs, just fill plugs

The only difference between the tool you (cal3thousand) have vs. the one I used is that the one I had runs through an air compressor and hence requires no manual pumping.

dzywicki

Really good info. I really appreciate the help on this topic. I'll get the kit from thectsc with Lifeguard 6, filter and gasket and I should be good to go. Thinking I'll go Amsoil for the transfer case and diffs. My VAGCOM should be here tomorrow so I can start poking around with that too. I'm used to the fluid temperature check. I had the same thing on my Mercedes, but I just used an IR temperature reader on the pan. At least that had a dipstick to make it easier.

dzywicki

Pulled the passenger side wheel and found the fill plug. Also got to look at the front suspension. All the ball joints look to be in good condition and all the rubber bits look good too. I was a bit worried with 67k miles. I'm assuming the previous owner did not drive it really hard, which is fine with me.

I'm assuming the fill plug is what I have circled in red?

raj99

Yep you've got the right fill hole. Btw are you certain you need ZF6 vs ZF6+ vs ZF8