Hi,
I did a fair amount of driving over the last couple days (what with the holiday and all) in my 1992 900 (NA). All was well yesterday, and most of today, until right around dusk. While driving on the highway, the front end of the car suddenly started shaking violently. I backed of the accelerator, and it seemed to abate. Turning left or right had no effect. I couldn't tell conclusively which side of the car was shaking, but it seemed like perhaps the right.
I pulled over, jacked up the front of the car (hydraulic jack and jackstands handy in the trunk/boot), and inspected things: wheel lug nuts, tire inflation, ball joints, CV boots, etc. Everything seemed OK, so I kept driving. And the vibration continued. I eventually determined that I could make it temporarily stop by stomping on the gas, or by laying of the gas completely. Cruising along with a moderate amount of gas, especially downhill, seemed to be the worst. When I got off the highway onto two-lane country roads (generally doing 45 - 50 mph), the problem did not manifest itself at all.
Based on the symptoms, I think the problem must be with the driveshafts. The right side inner driver was replaced within the last two years. CV joint problems generally manifest themselves only when turning, no?
Any and all suggestions appreciated.
Thanks,
John