That is wierd. I see it as four seperate things. the automatic transmission which I got the syn ATF and filter kit for it has its own drain plug and fill/check plug, the center differential right behing the AT with its own drain and check/fill, which drives the rear (its own check/fill and drain and drives the front diff which has a check/fill plug and is measuring fine with no ATF in the AT.

 

Ok. Yes because you dont put AT fluid in the diff's and there happens to be 3 of them on a quattro car. So this is why on the automatic the main part of the transmission is closed off from the diff sections of the housing. This is why on the manual transmission you just use 1 fluid and pour it right into the main part of the transmission housing.

 

Ah. Wait... what is an automatic transmission?

;P

 

Is the level plug you found above or below the axle? If you are trying to do the front diff fluid (not the center), and it doesn't mix with the Auto trans fluid, you might just have to pull the axles and suck it out. I worked for 5 years on Audi's in a dealership and I can honestly say I've never replaced the front diff fluid on an Auto quattro car. The Porsche and VW transaxles are integrated with the transmissions. I guess I just never had an Audi come thru with that request!

 

The check fill plug is above above the axles and I don't see the drain. I thought it may have been one of the bottom housing bolts but I didn't want to break any seal. the car has 160k on it and judging by the tightness of the plugs and knowing the previous owner, I doubt if it has ever been replaced. I guess I will just try to siphon as much out as possible and top it off with some fresh...gotta be better than the old stuff. I hate the smell of diff lube.

 

Have any of you figured out the final solution to fluids?

Do the automatics have 4 fluids?...

1 - Front diff
2 - Center diff
3 - Rear diff
4 - Transmission


How about the manual transmissions? It sounds like the manual B6s have...

1 - Front diff
2 - Center diff / Transmission (both get the same fill and drain plug)
3 - Rear diff

 

According to the manual I have (just a cheap over the counter deal)

The center diff & front diff grease is the same 75w-90 synt
the rear calls for 90w synt (I just used 75w 90 synt)
and the tiptronic the synt AT fluid

and I siphoned what I could out of the front and topped it off.