The truck that is. At about 30mph it starts moaning, and I can feel it in the shifter (NV3500). At first, I thought it was trans, but it comes on at 30mph no matter what gear (just easier to hear in 4th and 5th). I've changed all the fluids with the correct ones (except 85w-140 in front diff but it moaned before that). It sounds like it's coming from the front. I jacked up the front and the hubs feel tight. I also hear the telltale squeek squeek sometimes at speeds <30mph of bad U-joints. Again, it sounds like it's coming from the front, but shouldn't that driveshaft not be moving? When parked and in gear with the truck off, I can spin the front driveshaft freely, so it isn't engaged (it also squeeks when I do this). My question is how should I start diagnosing this? Remove front driveshaft and see if it goes away? If that doesn't that work can I reattach it and remove the rear driveshaft and drive in 4WD (FWD) to see if it is actually in the rear? Thanks

 

The front shaft still spins. Remove it and see what it does. Don't remove the rear one and drive it, you lose the tranny fluid.

 

Alright, well pulled the front driveshaft, and no change. It only happens when it is accelerating. Push in the clutch, and it disappears no matter what speed I'm at. I can feel the vibration in the shifter, but not so much in the transfer case shifter. So, this narrows it down to tranny, rear driveshaft, and rear end. When coasting under 30mph I can still hear a scrap scrap noise like something scraps once every rotation. When I changed the rear diff fluid it had fine metal particles on the magnet, but I'm not sure if it was more than acceptable. All the teeth were intact and the gears weren't what I'd call sharp (certainly wouldn't cut you). I shook the rear yoke with the driveshaft off, and it didn't budge. One thing I did notice while changing the TC output shaft seal was the rear shaft coming out of it had a little play in it (some front to back). If it had to do with TC ring clip wouldn't I feel that in the TC shifter though? Also, when I checked the rear U-joints they seemed fine. All caps were solid and no play. Any help appreciated.

 

how old is the clutch ?? maybe a piece if friction material has come loose and is scraping the housing ?

 

I have no idea, but it feels firm and has no signs of slippage.

 

I think I just found it. 2 bad rear wheel bearings. Which each side jacked up alone, I can move each wheel vertically back and forth. The passenger wheel is the worst (understandable since it is the main drive wheel). It has about 5-6mm of vertical play. I thought the truck felt a little loose in the rear, but I've never experienced rear wheel bearing failure before, so didn't put it together. How bad of a DIY job is this?

 

I'm a lazy ba$tard, so I'd just find a diff that would work that had an LSD in it. But that's just me.

 

I shall play zman for a brief minute; thread titles man, thread titles.

No one is going to search for "she likes to moan"... At least not on this website...

 

And someone that looks that up on google with OTHER intentions will find it strange to find this link.