Which Castrol to put in Audi TORSEN diff.?

[bar1]

SAF-XO 75W/90 (API GL5) or TAF-X 75W/90 (API GL 4/5)?
What about front and rear diff? Suggestions..

 

[moribundman]

Well, you don't mention what model year your Audi is, so I can't really help you. My '96 A4 Quattro requires a 75W-90 GL4 in the tranny and torsen (they obviously share the same fluid -- the torsen is bolted to the tranny) and a SAE 90 GL5 in the rear differential.

There are those who will tell you that a modern GL5-rated oil will not damage the yellow metal components in a tranny that requires GL4. I'd get that in writing and signed.

A dual-rated gear oil (GL4/5) should be fine.

 

[bar1]

It's a '96 S6 2.2 TQ Avant. It has autotranny so torsen does not share fluid with tranny.

 

[moribundman]

The center differential in AWD models with auto tranny requires API GL5 SAE 75W-90. Sorry, my crystal ball didn't tell me you had an auto.

As for the "front differential," the OEM fill is ATF Esso LT 71 141/Audi ET-Nr. G052 162 A1.

 

[bar1]

Thanx