My 1984 240 DL wagon recently started vibrating/shuddering like crazy, but ONLY between 40 and 50 mph -- keep below 40, or above 50, and it's smooth. The vibration stops, even between 40-50, if I take my foot off the gas. The rumble sounds from the rear. My best guess is out-of-round tire. I recently had a tranny rebuld and an alignment (but all was fine for a few weeks after each repair). Anything to consider other than bad tire?
Could be a drive shaft imbalance--presumably, the shop knew to keep the two pieces of the drive shaft aligned. Check the support and support bearing as well. Gary
Check the U joints on the driveshaft, my brother's 240 started doing that and one of the joints had lost it's needle bearing completely.
Thanks very much, folks. My Volvo guy replaced my U-joint ($120), and all is well. You good folks saved me from buying tires for nothing. Thanks again.
