Is this a ujoint or something else? Noise only happens in reverse gear with engine running, no noise when backing in neutral with the engine off. Noise disappears when in forward gear. 
 

 

Yeah Andy, at the slow speed while backing up (I'm guessing here) since your rig is a 2000 do you have drum brakes in the rear? I'd jack up the rear, both tires off the ground, put the transfer case in neutral and hand turn the tires to see if you have a brake pad just slightly dragging. It's just a guess...that moaning reminds me of brakes. Again, only guessing here, my 2001 has four wheel disc brakes and I'm aware of the "glide-pins" becoming contaminated and causing drag also.

 

W-T 

Hey @W-T my rears are drums, I’ll try that and report back, but it only does this when in gear (reverse) if I’m in neutral and coast backwards the noise goes away. 

Sounds like the shoes are rubbing too tight need to adjust, unless the emergency brake is staying on slightly.

 

Don't listen to W-T he hardly ever drives his truck so it squeaks like that all the time.

When the transmission is shifted to reverse the engine, transmission and front half of the drive line shift to a position that's a little different than drive or neutral.  The drive shaft maybe rubbing due to a worn or misaligned transmission mount or center support bushing.     

Thanks @IBMobile, and when you say transmission mount do you mean transfer case? 

does it squeak if you roll it backward in neutral?

 

I have used W-T's method of running it when on jack stands and its very dangerous to go near it though so be careful when you get out to listen where it's coming from.

 

I roll my truck backward in neutral almost every time after starting to see if my calipers are stuck on.

@JAG1 no, backwards in neutral there is no noise. I’ve let it roll back in neutral with the engine off and with it running…the only time it squeaks is in reverse with the engine on…same noise with or without brakes applied. 

So be careful and do as W-T suggests. but, again be careful @Andyba20

If your going to check the driveshaft I woulds suggest just pulling the entire shaft out and inspect. Its very difficult at time to feel a bad u-joint while it mounted even with the rear axle off the ground. It will show up better with the shaft removed. Matter of fact that is a video I'll be producing here soon doing Thor's u-joints in the rear I've got a vibration at 65 MPH.

 

As for the brakes drums its possible to have a broken spring or hardware dragging in the drums so it wouldn't hurt to pop those tires off and inspect the drums and hardware for any damage and repair. There is rear drum hardware kits you can pick up at like a NAPA or similar store.

I will inspect the drums, but if it was a brake issue wouldn’t the noise be there regardless of the gear or engine on/off? I wish that video was a little better, I know it’s tough to see. Thanks for all the suggestions everyone. 

2 hours ago, Andyba20 said:

when you say transmission mount do you mean transfer case? 

Whatever attaches the transmission/transfer case to the crossmember.

I've seen where one shoe lost a nail and spring it would be fine forward but made all kinds of racket in reverse. Just the loose hardware can do that. Worth it to investigate both rear brakes and driveline.

14 hours ago, JAG1 said:

I have used W-T's method of running it when on jack stands and its very dangerous to go near it though so be careful when you get out to listen where it's coming from.

 

I agree that this is dangerous, but I just wanted to clarify what W-T posted.  He does not mention anything about starting the engine and shifting into a gear.  He does mention to "hand turn the tires". 

 

18 hours ago, W-T said:

I'd jack up the rear, both tires off the ground, put the transfer case in neutral and hand turn the tires to see if you have a brake pad just slightly dragging.

 

- John

Your right john as usual. how can you be so right all the time?

33 minutes ago, Tractorman said:

 

I agree that this is dangerous, but I just wanted to clarify what W-T posted.  He does not mention anything about starting the engine and shifting into a gear.  He does mention to "hand turn the tires". 

 

 

- John

Thank you @Tractorman indeed my suggestion was NOT with engine operating...

 

In several additional reviews of @Andyba20 video it is pretty easy to see the velocity of the rear universal joint compared to the turning speed of the tire/rim. In correlation of the sound it appears to me that an out-of-round break drum is coming into contact with a break shoe for a specific portion of the rotation. I referred to this sound as a "moan" having an elongated duration to my sense of audio discrimination. Squeaking, pertaining to the spin-speed of the universal joint would have a much more constant audio- report, over a 360 degree rotation. Again, not being with Andy when he's trouble shooting, only allows a guess however; I'm leaning towards the possible drum break assembly. I say it's a "moan" not a "squeak".

 

W-T 

Watching the video a couple of times, I agree that the "moan" seems to be in cadence with a tire revolution, not a driveshaft revolution (3.55 turns per one tire revolution).

 

Also, the previous posts and video are not clear as to whether or not the truck operator is controlling the reverse speed of the truck with the foot brake, or if the transmission selector is in "reverse"  This information could help with troubleshooting.  

 

- John

The “moan” is the brakes. It’s in reverse gear going slightly downhill with a 30ft gooseneck trailer hooked up. The “creaking” noise is what I’m chasing down. The creaking is heard in reverse gear up hill or down hill, brakes or no brakes. Coasting backwards in neutral there is no creaking noise, in forward gear there is no creaking noise.

That is good information.  I can't say that I can detect the "creaking" noise in the video.  Something that comes to mind is I believe someone posted on this forum (or the TDR forum) about a cracked or loose flex plate.  If I recall correctly (which happens less and less), the noise only happened in reverse, which seemed odd.  It had something to do with how the torque converter operates differently in forward than in reverse.  I don't remember the details.  

 

If a failing u-joint is suspected to be making the creak, there is an easy test to eliminate or confirm this without removing the drive shaft.  A u-joint that is failing to the point of making noise generates heat at the exact failure point.  Take the truck (after setting a few hours) for a drive.  After no more than 5-10 minutes of driving, pull over and feel each post on each u-joint by hand.  If there is a significant temperature difference, you have probably found the problem.  I have used this procedure a few times and in some of the tests, I actually marked the posts on the u-joint where I felt the heat.  Each time, upon driveshaft disassembly, I had correctly identified the failing post / posts.

 

- John

Here’s another video…sure enough it happens when brakes are applied. When it’s on the ground it makes the noise regardless of the brakes unless they are dragging from being held before I shift to reverse. (Noise at the end is me putting it in park while the wheels were still spinning) 
 

 

Time to pull the drums...