Hello-

I just put my project car ('65 122-2dr) on the road, runs great, but has a bad vibration in it at speed (over "65mph"- according to the speedometer).

The car hasn't moved under its' own power since 1983. I bought it without an engine/transmission about 4 years ago, and put in a new engine/M41-J type tranny.

I've been running around in it for about a six-months (a mile or so at a time), and noticed the vibration then, but thought it was the old, worn out tires. So, after new outer rims (6" wide), new tires (205-65R15), new shocks (Bilstein's), and changed out the drive shaft with a known balanced one, it still has the vibration.

So, I jacked up the car, checked the oil in the differential (-it's full), then ran it at ~30mph. A definite whining sounds, like something rubbing in the differential area (checked the tires for rubbing-no tire rubbing). Looks like the differential has a drag in it also (rear wheels spin freely by hand), noticeable rotation in the differential, like a pulsing action. At first I thought it was the rear bushings, but now, because of the whining, I think the differential is bad. The noise is also there when I hand spin the wheels, sounds like the sound of sticking a playing card in the spokes of the bike tires, but faint.

Any other suggestions what the problem might be, or is the differential needing replacing???

Thanks-

Paul