Replacing rear driveshaft rear U-joint
 

Hi folks,

I have diagnosed a noise on my truck and I think it is a bad rear driveshaft U-joint (where it connects to the diff). The truck is a 2007.5 3500 DRW 4x4 QC longbed, 68RFE with 3.73 diff, 81k miles. I hear a "clunking" noise while accelerating (nothing while coasting or decelerating) that is vehicle speed dependent. I raised up the rear of the truck off the ground and drove/spun the wheels at low/medium speed, and was able to hear and locate the noise at the U-joint/rear diff. I'm guessing I have a bad U-joint. Two questions:

1) How difficult are these to change? I am a pretty competent shadetree mechanic with a good set of tools for my racecar, but I have no tools specific to my truck.

2) What should I replace it with? I hear that the Spicer U-joints are preferred - does anyone have a part number handy, or any info? the OEM one was obviously pretty crappy, so unless the stock replacement part is somehow better then the one from the factory, I would like to put something else in there that will last for a while.

I may also change the diff fluid while I'm doing this, I need to search for a few threads about how to do that, but any advice on that would also be appreciated.

Thanks for any help folks. I hate to take it to a shop if it is something that I can handle in my driveway.

I had rear u joint lock up at 28K , my driveshaft was steel , it was heavy to deal with . My ujoint was held in with plastic material that needed to me melted out before cross could be removed . It has a low melt temp , I heated my with a propane plumbers torch while I used a press to remove the cross. It was rusted into the and took a bit to remove it . I made a piece to support the yoke from crushing by splitting a piece of tubing of the correct size and placing it against the joint inside the yoke . Once it moved it was just press it out and press new one into place . I used Moog greasable replacement joint . It has worked fine with no issues .