Anyway, the fix is to eliminate the vibration. Your correct pinion angle is dependant on the angle of the tailshaft of the trans. Say you trans points down 4* your pinion should point up 4* (theoretically). But with a leaf spring rear you must compensate for spring wrap by appx 2*. So you would be closer to 2* up on the pinion. So, you have to measure the angle of the tail shaft and go from there.

Does this make sense?

I'll post the procedure tomorrow.

Road test the car and note the level of vibration and the speed that it is most pronounced.
After the road test support the rear axle with two jackstands and chock the front tires. Remove the rear wheels and drums. (Do not apply brakes with the drums off) Mark the wheels and drums before removal to assure reassembly in the same positions. Run the car to the same vibration speed as the road test. If the vibration is still there it is probably an untrue or out of balance driveshaft. If the vibration disappeared have the rear wheels spin balanced on the car.

1- A car is normally more sensitive to driveshaft unbalance at the rear of the shaft. Mark the circumference of the shaft approx. 6" forward of the rear weld in 4 equal parts. Number the marks 1-2-3-4 around the shaft.
2- Install one Whittek type hose clamp around the driveshaft tube with the screw of the clamp at mark number 1. Test run the drive shaft in the vibration speed range. Note any changes in the initial vibration, better - worse.
3- Move the hose clamp screw to mark number 2 and re-evaluate the vibration and note any
changes, better - worse.
4- Repeat step 3 with the clamp?s screw at positions number 3 and 4.
(Note: If no difference is noted with the clamp added in each of the 4 positions the problem may not be driveshaft unbalance.)
5- Set the hose clamp?s screw to the best position, opposite of the worst position. If two adjacent positions were equally good, place the clamp?s screw between the two positions and re-test.
6- If unbalance is still present with one clamp in the best position install one more hose clamp with the screw in the best position and re-test.
7- If unbalance still exists, the combined weight of the two clamps may be excessive. To reduce this excess weight, rotate the two clamps screw away from each other approx. ?"each an equal distance from the mark. Re-test
8- Continue to rotate the clamps apart until the balance is best.
Note: slight vibration felt in the car on jackstands may not show up in a road test which is, after all, the final determining factor.
9- Install drums, and rear wheels.
10- Road test the vehicle.
11- If still unacceptable, mark the front of the shaft at 4 positions and repeat steps 1 through 10.

Good luck,

SteveW

The DS angle may be your problem with wearing out the joint. The front joint would be at a 9.5* angle which is a bit much I think. If the trans is 7* down the pinion should be about 4* up. This will reduce you u-joint angles too and help with u-joint wear. What u-joints are you using? I would try playing with you pinion angle and see if the problem gets better.

coupe3w