Today i pulled the driveshaft back out and fired it up on the jackstands and ran it again..It did NOT do the pulsating/phasing vibration with the driveshaft removed! I checked the shaft and u-joints over again and reinstalled it.......
so, if it DIDN'T pulsate without the shaft, the question comes up in my feeble mind, who balanced it, and was the shaft high speed balanced ? [higher than the normal truck shaft builder]
if you mentioned before this answer, i apologize for not remembering.
glad you discovered the broken mount.
