Ever since I installed the 605 I've been plagued with a bad vibration in the driveline. I've checked driveshaft angles 5-6 times, broke a tailshaft housing, changed trans mounts twice, and had the tires balanced. It still had a bad shake.
Today I put the truck on the hoist once again determined to find the cause. I pulled the tires and brake drums and was going to go through everything again. I decided to check the driveshaft again with a dial indicator. I got the the rear of the shaft and did a double take. The new U-joint I had installed when I put the new motor in showed clearance between the caps and the cross. I could move the shaft up and down, and side to side .050-.100. I thought I must have got the wrong U-joint. I loaded up the driveshaft and headed to the parts store. I brought it in and showed the parts guy the problem, we looked through the books and measure for an hour. Nothing available, I said you know this one would work if the snapring grooves were spaced farther apart. We checked it against the one he had listed for it, everything was the same as mine except the snapring grooves were farther apart.
The one I had installed must have been machined wrong during manufacture or had the wrong caps in the box. I took the new one back to the shop installed it, run the truck up to speed on the hoist, smooth as silk.
I never noticed the problem and I'd had the shaft off 3 times. The rubber seals were holding it centered until I got it worn in I guess. I've spent many sleepless nights trying to figure this out. I'd lost a needle in the original joint and installed a new joint when I installed the motor. Of all the crazy things to jump up and bit me this is in the top 5. Dave
Dave