I've been having a problem with a slight pulsing / vibration in the truck for the past couple of months. I first noticed it after installing the rear lift blocks and then towing my Jeep (~6500lb load). Ever since I have slightly noticed it but it hasn't been anything that kept me from driving it. This past weekend I was towing again and it got really bad, very noticable and worse than before. It seems like a U-joint issue or something but I can't feel any noticable play in the rear driveshaft. One thing I did notice, however, is that the rear output of the tcase has a slight vertical movement when I press up on the driveshaft. I'm not sure if this is normal for these tcases or not. Anyone else know if this should be the case?

I think I'm going to take the rear blocks out and see if the vibration goes away, and maybe try and bevel them slightly if this does help.

 

Nobody? Can someone at least go outside and see if their output shaft has play in it? single piece rear driveshaft would be best I guess.... Thanks!

 

Mine does and I think about it all the time. Just never had it checked. I find most things sloppy on these trucks when it comes to driveline and suspension.

sorry I can't be more help, but I do have the slack you are talking about.

 

And I'm assuming you don't have any kind of vibration while towing then, huh? Maybe my U-joints ARE bad and I just can't feel it with my hands. Anyone know the part number for the rear driveshaft joints? I have read it is a 1350 but I wanted to be sure.

 

Mine has notable play in the transfer case output shaft, and no vibrations, leaks or other problems...

 

OK, thanks guys. Sounds like the play is normal and shouldn't cause the vibration, so I definately look into the U-joints. And of course remove the blocks to be sure.