In Reply to: International cry for help!!! M3 with BAD handling posted by David Bates on August 15, 2001 at 07:53:55:
Here are the most likly things:
First...DO NOT RUN TWO DIFFERENT TIRES FRONT AND BACK. Let me be clear on this point, DO NOT RUN TWO DIFFERENT TIRES FRONT AND BACK. The reason for this is that the sidewall response and chariteristics are critical for correct handling. I have made that mistake myselfe, and it felt like the car wanted to go off to where ever it wanted, only taking suggestions from me. I would get a set of 4 identical tires on identical rims, check the air pressure (205/15 - 36 psi front 38 psi rear) and see if that fixes things.
Second...Jack up the car, either one side at a time or by putting it on jack stands. Lock the steering to prevent movement. At each corner, grab the tire first at 12:00 and 6:00 and try to move it in and out at the top and bottom (wiggle it HARD) do the same at 9:00 and 3:00. If you have play, work with someone else (use jack stands if someone goes under the car) to locate the source of the play. If the wheel bearings, either front or rear are weak, or a ball joint is bad, it will show.
Third...in the picture these are the rear end parts that can go:
#3 - This is the sub-frame bushing. if one or both are bad the entire rear suspension will move about. it is held to the car's tub by bolt #2 which goes thru the floor pan, and is held in the correct alignment by brace #4. if either the mount point in the floor or brace #4 is loose or damaged, movement is likly. I have had one fail after a short period. Check the space between the lowest part of the tube that the rubber bushing goes into, and the metam flat at the bottom of the bushing itself. there should be 5 - 10 mm, and even on each side.
#9 - there are two of these per side.
Check the welds on the attachment points on the subframe.