on the 84 245Ti...

recently changed the ujoints on the rear driveshaft (ran out of time; will do front soon). Motor mounts OK. No leak at trans tail shaft so presume bushing is OK. Rear trailing arm bushings (TAB) are shot and I think the differential flexes more than it should (on list of things to fix). Tires were recently balanced, but they are also showing wear after 30k (Bridgestone Potenza radials). I have not had the driveshaft rebalance after installing the ujoints.

Anyway, with those preconditions listed above, the car has a prounounced vibration which varies with speed. Gets real "bumpy" at around 25 mph then lessens but you can still feel it. Almost like flat spots/out of round in tires. Also seems to vary depending on downhill or flat and pavement surface.

Since TAB are shot and am probably getting metal - metal contact/transfer with a moving differential, could this the most likely cause of the vibration?

By the way, just realized this: Haynes and Bentley show conflicting instructions concerning drive shaft installation phasing. Bentley says all driveshaft yokes should be parallel. Haynes shows the very forward drive shaft yoke (front shaft) 90 degrees off from the rear yokes..

Any insights/opinions appreciated

Thanks, Robert