Update on the driveshaft.
I took it to the driveshaft place when they opened at 8:00 this morning, then got home about 1:15. The good news is it’s all fixed, spinning like a top!
And maybe I should put this in the “today I learned” thread, but it still seems appropriate here. Today, one day after my 70th birthday, I learned again you’re never too old to learn something new (and what a dummy you are).
I never knew, I never even suspected, that when you put the universal joints on the driveshaft, they all have to line up in the same orientation. Not knowing that, when I put the front driveshaft back in, the U joint was at about a 45° angle from the U joint in the rear, and that was the cause of the vibration.



I always like to learn new stuff, and I actually learned $385 worth. Considering the 300 K+ miles on the truck and drivetrain, and the weird stuff I’m doing with it, I went ahead and had it all checked for being straight and balanced anyway. But it was an expensive lesson to learn.
When it was all done, and I was just shooting the breeze with the guys in the shop, one of them said “did you know you could replace that with a one piece driveshaft?” I wonder why nobody on the forum mentioned that…