So, I was initially told (or maybe I just assumed) that the rear dif of the stock RS6 would work fine with the 01E swap. I'm now assuming this is true of the standard 01E 6 speed U.S cars that have a final drive of 4.11:1. From what I have been able to gather, the FTL coded trans (which I think came from a 00-04 euro 2.5l a6 tdi) has a final drive of 3.89:1.
Now I have a small dilemma. First, I've been driving the car this way. I hope I did not damage the trans (not a big deal with the rear dif as it will need swapped). Second; I don't really want to wait four weeks for a dif from U.K. and pay huge shipping cost (doesn't matter if I have no other option). But it seems there may be the same dif used in the U.S only with other models of Audi/Volkswagen. When I search for replacements, no one lists (or even has knowledge of) the final drive of the rear dif. The part number I have been able to find from a UK sourced rear dif that will work lists the part number as 01R525053
Does anyone have any knowledge of a U.S sourced rear dif that will fit and uses the correct final drive?