Odd 4 wheel drive noises and operation

[deweiser]

I haven't had to use 4 wheel drive for the last 4 months till finally the snow got real deep. It engages fine but when you pull off you hear clunking and somewhat feel a small vibration every time it clunks. At first I though CV joint till I inspected it and the CV was fine. Later on I tried pulling a friend out of the snow but noticed it clunking real bad when the chain was taught and my front tires weren't moving. I got out and had my friend get in and give it some gas. The front Drive shaft spins normally but the front tires visibly shake with each clunk. On solid land it doesn't make a noise even with 4wd engaged but the second the rear end spins the front clunks away

Before I borrow a lift at work does this sound like the 4wd isn't engaging all the way or is my ring and pinion shot?

 

Its lifted and been through alot of mud but it always gets a go through including both differential fluid changes (80w-90 conventional) after every weekend in the pits

 

Any thoughts?

[gmtech4]

I haven't had to use 4 wheel drive for the last 4 months till finally the snow got real deep. It engages fine but when you pull off you hear clunking and somewhat feel a small vibration every time it clunks. At first I though CV joint till I inspected it and the CV was fine. Later on I tried pulling a friend out of the snow but noticed it clunking real bad when the chain was taught and my front tires weren't moving. I got out and had my friend get in and give it some gas. The front Drive shaft spins normally but the front tires visibly shake with each clunk. On solid land it doesn't make a noise even with 4wd engaged but the second the rear end spins the front clunks away

Before I borrow a lift at work does this sound like the 4wd isn't engaging all the way or is my ring and pinion shot?

 

Its lifted and been through alot of mud but it always gets a go through including both differential fluid changes (80w-90 conventional) after every weekend in the pits

 

Any thoughts?

 

if the noise is real loud under load its the chain skipping over the gears ,,

 

just do a brake stand in 4wd ,it should do it ,,

 

sounds like the truck is comin apart lol

 

if you can get it to misbehave you need ,2 new gears and a chain AT A MINIMUM ,,pump saver etc etc

[deweiser]

I don't think it's inside the transfer case, doing a brake stand the front drive shaft still spins in time with the rear. My thoughts are either on the clutch pack not engaging in the front end if that's a thing, I'm not sure I haven't pulled an electronic IFS axle apart before just a solid axle.

[gmtech4]

I don't think it's inside the transfer case, doing a brake stand the front drive shaft still spins in time with the rear. My thoughts are either on the clutch pack not engaging in the front end if that's a thing, I'm not sure I haven't pulled an electronic IFS axle apart before just a solid axle.

 

There is no clutch in the frt diff.

 

Have the right axle shaft/tube removed and inspected

[newdude]

99 2500? Is it push button with an auto button at the top? Clutch pack would be in the transfer case if thats the case as most of those 2500 non HD trucks had the Autotrac NVG246 transfer case.