Hi,
Lately I've been noticing a slight wobble from the back end when going over uneven road surfaces. (not bad surfaces, just like over manhole covers or the like). Its a 996 C2, 2001 with 100,000 kms on it.
I had it serviced at the dealership last week and asked them to look at it, but they found nothing. They suggested I buy new rear tyres (Pirelli P Zeros currently on it, and ad they quoted $870 per Tyre).

Car is under warranty for another week or so with them, so its not in their interest to find anything.

Has anyone else experienced this at all? It just feels a little loose, or seems to shimmy a bit when going over surfaces that arent competely flat. Its not like a massive movement, but definately there.
Any ideas on this, or what to look for or should I take it to an Indy shop for a second opinion?
Thanks,
Dave

 

The only thing I can think of that causes movement in the rear end of the car is tramlining. This occurs most frequently on asphalt roads that see lots of truck travel. The trucks make depressions or ruts in the road. The wide rear tires of a 996 don't allow it to sit with one tire completely in each rut, so it's constantly wiggling around, trying to get into the ruts. Is it possible that this is what you are feeling? I certainly don't notice this going over manhole covers, but I'm wondering if this could be your issue. It also sometimes happens on grooved pavement...

 

Hi Dennis,

Thanks for the quick response. Dont think it is that, as I felt it today when I went over a manhole cover with only the one wheel.
I have felt what you mention on really worn roads with tramlines in them, but this is somethink different.
Cheers,
Dave

 

You might want to check all the rubber bushings in the rear end including control arms and sway bars.

 

How old are your shocks? Sometimes dealerships will not replace a worn item like shocks if there is no physical evidence like leaks.

 

Order a m030 kit and new front n rear control Arms and rear strut tower brace n f and r sway links from a reputable company and your car will handle like mine . No problems ...

Btw I think u need to look at bushings n wheel play... Sway links on 996's are a week point in the suspension

 

When was your last alignment?

 

Hi iv got the same problem on my c4 and I can't figure out why, I no what your feeling mine is on left rear wheel when going over man hole covers it's like it's skips from side to side just on that wheel , if you have fixed this what was is be appreciate the help

 

I had similar experience on a BMW Z3 I had. The car was straight up scary with wandering and instability. Front tires looked almost new. Rear tires didn't look that bad, but I went ahead and replaced the rear tires on advice from BMW forum members. Completely fixed the problem and the car drove rock solid. Handled great, actually. I'm glad I tried that first, because I was convinced it was arms and bushings, and was about to start swapping out all suspension components for no reason.