I was given a 2006 A4 2.0T Quattro Tiptronic sedan as a loaner this evening as the dealer's service had not gotten my A6 Avant worked on as promised. I have been really impressed with the car so far, but I noticed when I was checking out the turning radius that when I the wheels are turned all the way (almost to lock) at low speed in a tight circle it feels as if something is almost slipping, rubbing or something in the Quattro drivetrain several times per 360° circle. (sort of like the differential is quite keeping up). Is this normal? At all other times the drivetrain and steering feel great.
Just kind of freaked me out when it happened though at the same time am impressed with turning radius (feels actually even tighter than the specs say). BTW the car is equipped with 235/45-17 tires and rims.

 

I am pretty sure it is the differential.
It could also be the rubber boost on the CV joint making the noise but not very likely.
However, if there is constant noise when you hold the steering at either lock and keep turning (without moving the car), that would be the steering pump or rack.
My car 97 A4 make that noise but there is no rubbing.

As for the tire size, it is the standard size for the year so there should be absolutely no rubbing.

 

uh yea.. for future reference, the power steering system on the audi isnt exactly the most bullet proof, so aviod cranking it to lock if you can

 

Thats pretty normal of any AWD car that I know of. I have front trak, but I drive Quattro/4 Motion all day at work and notice the same thing on pretty much every one of them.