This is the first time I had to drive in 4x4 on the road this year and I have some noise. I will try to explain it the best I can.
When on the way to work today started off in 2wd everything fine until I slide through the first stop light. After that I stop and lock the hubs in and use 4x4 the rest of the way. When I would let off the gas the would be a noise coming from the front. It is a grinding type of noise kind of like the tires rubbing at highway speed. Lasts for only a second as soon as I let off the gas then goes away. On my trip home I leave the hubs locked in but take it out of 4x4 and the noise gets alot worse and it feels like it drives rough like cupped tires. Put back in 4x4 and all smooths out but still makes the grinding sound. Only now it is a little worse. When I let off the gas to go down a hill it is a constant noise. I also noticed that it only makes the noise when letting off the gas or when the engine is slowing the truck down.Also noticed that when letting the engine do the braking and noise is alot worse when I hit a dip or bump in the road.
For a little back ground on my truck. Just lifted it 6 inchs this summer and installed a set of warn manual locking hubs. All the ujoints and all the 4x4 parts looked real good last time I was under it.
We are supposed to get upto 12 inchs of snow tonight plus what we got this morning so if anyone can help I would appreciate it.

 

Hmmmm, this may be what i had/have happening. I had a post or two trying to figure out what it could be. I origionally thought it was my tcase, but it wasnt making sense. I cracked the truck the other night, and in my attempts to get out, i blew the splines off the slip yolk on the front DS...and it was a sloppy slip yolk to begin with, but got worse and worse....so im hoping it was that, or a ujoint on it. Mine would make no sound with the hubs out...Hubs in, it wouldnt be TOOO bad, but in 4wd, wow. it would sound like its binding, grinding churning, etc, but only under a bit of a coasting type of situation. or under braking it would shake the heck out of the truck. and now im positive that the slip yolk is to blame (havent put the replacement shaft in yet tho)
Brian
Good luck

 

Check, front fluid level, every u-joint for play including the 2 on the driveshaft and the 3 in the front axle. Check for play in the slipshaft in the front axle and the one on the drivehshaft.

 

I checked the ujoints and a bunch of other stuff today. Pulled my lock out caps off and they look good also. The noise doesn't seem to be there much today.
When I put the lift kit on I know that we bent the dust sheilds so I am wondering if snow is getting packed in around them but that doesn't make alot of sence. I didn't see a slip joint in the driveshaft maybe I just didn't notice it. Where is the one in the axle?

 

on the axle it's be on the passenger side, you'l have to look at it from the backside of the axle. There will most likely be a rubber boot over it. On the front driveshaft same thing, it'll be under a boot

 

mines doin the same thing, only i know i need a driveshaft ujoint, i'm gunna change it this coming week, i'll let ya know if that fixes it. Other than that i'm wondering if its just play in the transfer case chain...

 

Slack it the chain could cause a grinding sound if it hits against the case, if the symptoms worsen, and it does it in 2wd, the issue then would be the tcase oil pump. You can try taking out the front driveshaft and locking the case in 4hi, if it still makes the noise, the problem is within the tcase.

 

thats the plan...when i pull the shaft out i'm gunna run the case down the highway in 4high, then i'm gunna put it back in 2 wd and run with the hubs locked and no shaft...see what that does....and then i'll go from there.