Hello!
Does anyone knows if there is any difference between central differential in V6 vs V8 models? Looks like on my 2003 A6 4.2 torsen diff is going out... Here is my car symptoms: ABS light is on. Error code about rear right ABS speed sensor. You can hear clanking noise when you start driving and you can feel that torque applies to each wheel randomly. Feels like ABS engaging on each wheel, but i think its not brakes. I have disconnected ABS/ESP Bosch 5.7 module from ABS pump - same feeling. Lifted car up - while turning shaft, you can hear clanking noise inside central diff..
I found two corresponding part numbers for this diff (01L409751 and 01V409751). I am still trying to find out if this differential, part# 01V409751 from 2003 A6 2.7T with 5HP19 tranny, will be identical to this differential, part # 01L409751 from 2003 A6 4.2 with 5HP24 tranny. Parts numbers are different, so i am guessing something may be different between them...

 

I don't know if it will fit. But I can offer more information to you. The 01L409751 for the 5HP24 is the 5sp auto for 4.2 engine only. The 01V409751 is also 5sp auto 5HP19 but for the 2.7 and 3.0 engines. The p/n for your car 01L409751 is also used in the 02-04 a6q but the 4.2, 97-03 A8/S8 and the 03-04 RS6. So if you find any of those cars you can get the same unit from a parts car.

 

What is the exact code? It may not be the differential but ABS/Wheel sensor related instead. If you feel ABS kicking in, i.e. rapid clicking noise, then it may simply be dirty ABS sensor. Torsen center differential rarely fails. Even if it did, it would impact the front or rear bias, not individual axle.