Hi all,
'99 1500 4x4, 143xxx miles. Everytime I put my truck in reverse and hit the gas there is a loud squeaking noise coming from somewhere near the rear of the truck. It sounds like something is rubbing agains the tire, but I know that isn't the problem. The sounds speeds up with the speed of the driveshaft. It only happens when accelerating in reverse. If its in drive, there is no issue. If I let off the gas while in reverse, the sound goes away. Could my driveshaft u-joints be going bad? Or maybe something in the rear diff? The truck drives great otherwise, no shaking at highway speeds. Any help is appreciated, thanks in advance.

 

Check fluid in the rear diff, and while you are under there, shake your driveshaft, and see if any of the joints are loose.

 

Squeek, squeek, rattle, rattle, clunk, boom, D*MN. Go ahead and change your u-joints if you don't feel confident. Cheap insurance for something that could potentially leave you stranded when you least expect it.

 

The best way to test the u joints is to remove the drive shaft and hold the yoke in your hand and rotate it around. It should move smoothly. If it is stiff or makes any noise then the u-joint is bad.

Check your rear brakes while you're at it, brake fluid in the drums (leaking wheel cylinder) will squeak. Busted springs in the drums or low brake shoes will squeak/grind also.

 

u joints make more of a clicking noise than anything, ive replaced one on the rear driveshaft and the front axle

this is how you know they are bad
http://www.youtube.com/watch?v=_CfLDb1QDb0

 

I noticed a clicking or knocking sound from the rear when leaving from idle. Originally thought it was wear on my swaybar bushings but i lost my driveshaft soon after. This is on a 3rd Gen though.

 

The u-joints could be locked up and not have any play too.
My drive shaft u-joints didn't have any grease in them and they wouldn't budge by hand because the needle bearings had turned to rusty dust and were locking up the caps.
One or two of my caps were cracked too from heat too.

The only symptom I had was a low speed "squeak squeak squeak".

That is why I say to take the drive shaft off and move the yoke by hand. It doesn't take more than 10 minutes to get the drive shaft off so that's an easy test.

 

Yeah I had an axle u joint go out, this is completely different though. I'm 99% sure its coming from the u joint right in front of the diff. Its not clicking or anything like the axle joint did, it just squeaks loudly at every rotation of the driveshaft, only in reverse though. I sprayed some wd40 on the joint to see if that would help, but it didn't (not yet anyway). I do have a pretty good size diff fluid leak (leaking out of the speed sensor port), and the fluid is all over the rear diff, could this have anything to do with it?

I've only taken driveshafts off with a cutting torch, what tools do I need to do it the right way?

 

Definetely not a torch. Probably just a 3/8" wrench or whatever it is on the axle side. Pop the u-joint out of the yolk and the shaft will pull out from the transfer case.

 

I think it's a 5/8" wrench if you have the big bolts. If you have the bands then it's tiny, like 8mm. But either way, just a wrench.