My '86 245, it seems, may be nearing the end of the line at 241k miles.

Not long ago I started noticing a low-speed vibration that was pronounced at 10mph and went away completely by about 30mph or so. I took it to my friendly neighborhood one-man-shop import specialist, who put it on a lift and found a couple of issues. First, the four bolts securing the front U-joint to the transmission were loose. He tightened them. He also noticed that the torque rod bushings we'd installed last fall were already shot. Otherwise, nothing seemed obvious. Most of the vibration seemed to disappear after tightening the front U-joint bolts, so I drove it home.

I didn't drive it much over the next couple of weeks. When I did it was just short runs around town, and I noticed an occasional thunk, clank or clatter from the back which I attributed to the bad bushings.

One day, I took it out on the highway and noticed that, while the original low-speed vibrations were gone, the car now vibrated at higher speeds. I could feel it in my seat at 30 mph, hear it at 40 mph and felt like I was risking some sort of mechanical disaster at 50 mph. I took it back to the mechanic, who drove it up and down the street, shrugged and suggested the rear end might be shot. He was busy with another customer's car, and seemed to be losing interest in my problem.

Anyhow, I ordered new torque rod bushings, crossed my fingers and installed them and... no dice. Still the clanking, still the scary high-speed vibration.

The car has some serious rust issues and my wife wants me to junk it, but I'd hate to throw it out if there's a simple explanation / fix. Anyone care to venture a guess?