Folks,

My '87 SDL also vibrates starting around 50 and lasting to around 70. It is a faster vibration than a wheel ( and not as strong), so I'm guessing driveshaft / center bearing / or axle(s). So how to trouble shoot? Nothing is obvious at external glance, but I haven't pulled down the driveshaft cover yet either.

It was suggested in the past to CAREFULLY support the car and run it, but I would not feel good spinning things that fast. I did just see an ad in the paper for a local dyno shop. Anybody been on one? What if I was to mark the usual suspects with a white mark and have someone run it up to the vibration speeds on a dyno ( or a speedometer shop I would guess as well). Would they let us get close enough to shine a flashlight under to look for vibration?

Any other suggestions without just swapping parts?

Thanks,

Chuck with the well massaged bottom