[Romer]

Feel free to contribute to this

Originally Posted by Waggoner5

You have changed the geometry on the rear driveshaft which as a single joint shaft, is designed to run at -1.5 degrees difference between the output flange on the tcase and the pinion flange. I have seen trucks without the adjustable rears NOT vibrate because they are within the 1.5 degrees, but as Christo informs us, most likely the shaft will eventually. When you tilt the pinion up, you will have to run the Cardan shaft in the rear. They are designed to run with the cardan at the output shaft end taking all of the angle, and the pinion end being parallel with the pinion shaft. Your vibration being at such a low speed could possibly be patched by installing new Toyota ujoints because, the old ones may have a wear pattern in them from the previous height or it could also be that the slip yoke is worn allowing the shaft to rock back and forth in the receiver flange, but in the long run you will want to do the arms and cardan shaft. The arms are adjusted to be longer and need to be done on the truck. A simple straight edge is what I used on my truck to make sure the piion shaft is parallel to the driveshaft. I then measure the distance from the upper mounts to the frame to make sure each arm is the same length.
Gary