[s-cars] Are Front and Rear Wheel Bearings the Same?

[David Forgie]

Here is a bit of a wheel bearing story for you

"The problem is the caller had received from his parts supplier was a 443407625E, i.e. should be for a C3 (Type 44 Audi 100/200, 
not a C4). A C4 bearing should start with 4A0 because "4A" is our chassis designation (note: not to be confused with the B4 "A4"
 which is a model designation, not a chassis designation). This 443407625E bearing had the split between the two rotating parts
 about 18/18 and had little or no stepping. During the installation of the 443 bearing (using a Hub Shark) they destroyed the new
 bearing (either because of the 18/18 split or the lack of step).
 
The 4D0407625E that I used didn't make total sense because of the "4D0" at the start. (Aside: The 4DO407625E is an 82 mm dia OD by
 37 mm wide double bearing. More importantly, it is stepped, with a 13 mm wide x 45 mm diameter portion and a 23 mm wide x 43 mm
 diameter portion (to match a step on the hub.)

I asked Kate (about the 4DO407625E) and she said that is the bearing for things like the 2001-2005 allroad. Hmmmm.... A quick call
 to Wally at VM Autohaus (my local parts supplier, always good) where I had bought the bearing last summer. Wally checked a
 443407625E to confirm the 18/18 split and the lack of step. He also confirmed the 13/23 (ish) split on the 4D0407625E. He also said
 that was the part that had superceded a 4A0407625A, sometime ago. Since the "4A0" made sense to me as an UrS4/S6 (C4 chassis) part,
 I got off the phone and asked Kate about the 4A0407625A and sure enough, she says that it was dropped on Dec. 31, 1996 (in the
 middle of the 97 UrS6 model year) and superceded to the 4D0407625E. Ah ha!! It is all clear now (ish). 

Conclusion: 4D0407625E is the correct PN now; do NOT accept any substitutes (especially if they start with 443). ;>)

Added note: Make sure that the person doing the rear bearings knows that there are circlips involved that are NOT present
 with the front bearing housing.

REF: Wheel Bearing Housing 101: http://forums.quattroworld.com/s4s6/msgs/33797.phtml
     Rear bearing info: http://forums.quattroworld.com/s4s6/msgs/157581.phtml