The other day I noticed my truck making a tinging nosie when I backed up. I got underneath the truck and felt the driveshaft by rotating it back and forth and heard the nosie. Well it sounded like it was coming from the real u-joint, so I went and picked it up from advanced auto and installed it that afternoon. I go to back out of my garage and hear the nosie again. I got under the truck again and rotated the driveshaft, and heard the nosie again. What esle could be making this noise from the rear u-joint area?

 

Could be that something like gravel somehow got inside the drive shaft or maybe some slag from when it was welded up finally came loose and is rattling around inside. When you replaced the u-joint did you shake the drive shaft?

 

It only makes the noise under a load, acceleration, turning stuff of this nature. Doesnt make the nosie all the time. The nosie sounds like a wrench tapping the driveshaft when it does happen thou. I'm gonna try new straps and bolts for the rear u-joint. The u-joint had just a alittle bit of play from the straps. We shall see!!