Slip joint.

The average balancing place just chucks up the OD of the joint, spins it, and pronounces it fit for duty.

If the slip joint's worn inside, it will vibrate this- hopefully, the ouput shaft is still ok. The borrowed driveshaft solution seems to indicate that it's just the joint.

hth,

Toby


'89 V6 4dr- '4- Doris'