My 1985 380 se has had a vibration since 77k miles it know has 104k miles. At 80 mph constant speed the steering wheel vibrates for 5 seconds and then goes away feels like it cycles throughout the whole car but only to come back every five seconds.. This is so annoying that when driving hwy 395 or any long open road you just want to screem. Also, a vibration can be felt around 40 mph when getting on the gas.
Replaced- Wheels and new michelins-force loaded balanced- by dealer motor mounts- transmision mount- idle arm bushings - new billstien heavy duty shocks-and finaly new factory driveline.
Driveline has been re-indexed - flex disc are good. I cant imagine why my mechanic hasnt sugested replaceing the center suport I guess it looks ok. Another post said something about a torque converter bushing? Otherwise car runs great. I have heard of a driveline alignment tool set but can find nobody with this mystery tool. After indexing the driveline i didn't notice a change. Please someone help!