Yep, first snow in my 93 A4 B6 Quattro. I was ready for a nice stable ride, but was shocked by what feels like the *** end wanting to change direction all the time. Any ideas? The car is new to me, has 100K or the clock. Did this shimmy at 60, or at 40 MPH. Did it with traction control on or off. Tires are 40%. Again, feels like the rear is loosing traction, but very randomly.

 

I assume you mean '03 A4

I seem to recall last winter someone posted a similar thread with the same issue. as I recall they reported it seemed to be more prevalent going over bumps (ie: train tracks), where the rear just didn't want to track straight. unfortunately I don't remember specifically what the solution was.

try a search. I will look also and see if I can find it again. hopefully, someone that remembers will chime in.

 

I did a search, and found some stories on tires, and some on the diff fluid being low or needing to be replaced. The fluid hypothesis is based on the clutches not engaging right thus a surging of power from left to right. This would have the tires breaking loose left to right then catching again. It goes away under 40 MPH. I'm beginning to think it's a combination of tires and rear diff oil/clutch wear. I'll change the fluids this weekend, and repost after the next snow event. I'm in Missouri, so it may snow 10 more times or not again for a year!! Now that I think about it, it did wag it's tail once in the wet, so more signs the tires are dry rotted or the diff is locking up.

 

I had a similar issue on my car and the problem was worn tires. It started with the car slipping in the snow to the car slipping when hitting road bumps. I think the previous post is in reference to mine. The tires did not look like they were depreciated and I did not think that it would create hazardous drving. I rotated the tires and noticed a change in the way the car drove. When I replaced the tires the problem disapeared.

 

40% tire tread? If those aren't dedicated winter tires then that is DEFINITELY your problem, that may pass for allseasons on dry pavement but snow is another game...