I'm working on rebuilding a '97 4x4 2.4 cyl Taco (I do more bodywork than mechanical so I enlisted the help of a good friend), and we ran into a problem with the drive shaft. I got the truck at an auction so I just knew it ran, but when we recently got it safe enough to drive, I heard a metallic grating noise coming from under the truck. My buddy instantly deduced it was something to do with that CV part of the double-headed U joint on the shaft and jacking the truck confirmed this, so he completely refurbished the shaft (new u joints and replaced that little ball bering and brought it up to a drive line place to have it balanced). We remounted the shaft and all was well for about a week, and after only driving it to and from the parts store and bone yard that noise came back. Having the truck lifted and in gear with the accelerator down you can hear this nasty noise is coming from that CV part of the shaft (only when the shaft starts to pick up a decent bit of speed on it's rotation) there is no vibration, just this noise that almost resembles a heat shield rattling my buddy says it popping some metal popcorn. I doubt my friend will get this thing figured out any time soon. What could be the cause of this? The rear of the truck was pretty banged up but the integrity of the frame was in tact, all damage from it's accident was on the body. My only concern is that the angle got tweaked just enough to put undue stress on the ujoints and that CV, any thoughts? Thanks in advance, all.

 

Does the driveshaft have a center support bearing? If so, give that part a good look.