Maybe U-joint is the wrong term for it.. The manual called it a "flex join" if I remember right.. It's more equivalent to the CV of modern days.. they look like a 6" giant rubber donut which connects the two parts of the drive shaft and allow the rear wheels to move up and down independently and independent of the differential.. The two ends of the drive shaft had a fork yoke connected to the opposite diameter.  It's cute.. but a pain.  I replace the two donuts twice.  The other pain is trying to stuff a lot of the rubber bushing into their repective metal tubings.. till someone told me about putting the rubber part inthe freezer for an hours.. and it just pop in place.  

Yau-Man

>>> Larry Hamm <ldhamm@xmission.com> 09/25 9:05 AM >>>
YauMan Chan wrote:

Are we talking model cars here? Rubber band springs? All-rubber
U-joints? None of the five GT-6's (all three Marks) I owned were so
equipped, and I must have changed at least a dozen U-joints.
The tip for diagnosing rubber squeaks is great, should save lots many us
a lot of grief. Thanks!
Larry