So apparently it's AutoTrac since it has an Auto 4wd option and it uses clutches in the xfer case. Very likely the clutches are burned up since the previous owner drove it in 4wd for who knows how long with a bad rearend.

Gonna work on getting fuel to the other truck to make sure that one is fully functional and then find time to swap the trans an all.

 

Sorry again man, I thought that the truck couldnt move at all like something was locked up, causing it not to move (thats why I was asking about the rear). I have seen alot of those t/cases burn up the clutch pack that is applied by the encoder motor, causing 4wd not to work and 2wd to be fine. That will allow the front driveshaft to spin with no load but not able to with load. Just pull the t/case drain plug and check for more chunks.

You were also asking about the front actuator not engaging all of the way, that would cause the front driveshaft to spin all of the time with or without load.

^Guess I took too long to type this^

 

When my g80 exploded, the front pulled the truck on the trailer. Even while dragging the rear tires.

 

Yea that's what happened in this case. The G80 took out the rearend and they drove back to the shop in 4wd. Since it's a company truck for an oil company there's no telling how hard it was beat on during that time. That and the fact that it has just shy of 300k miles says it's likely the clutches.
While I HATE that I have to change the trans and xfer case so soon to get 4x4 going I'm glad I found the problem. I was hoping to swap the trans during spring so It's warmer but I want a 4wd for the winter so i'ma try to get it done asap.

I've changed trans on my 03 plenty of times to know what to expect. Just gotta compensate for the xfer case.

 

Now. Does anyone know what wire on the fuel pump is hot so I can see if the pump is any good on my parts truck. Not getting fuel to the rail and I think there may be a theft device that i'm not able to disengage. Just need fuel enough to start it and try out the 4wd

 

thats the signal wire to the fuel pump relay.

 

On a 99 and probably on a 00 as well the clutch pack in the transfer case was shimmed so tight that it takes a big pry bar in the front shaft yoke to actually slip the clutches any and thats with it in 2wd. Its stupid because you can completely wear out the front u joints and front diff and never once in its life engage 4wd. But anyway point is thats how tight they are with good plates, tight enough that it would probably at least roll at idle just on that amount of holding power alone. In 4wd good clutch plates should pull no problem. On Autotrac transfer cases as far as I know the split is 50/50 front to rear. The clutch pack forms a solid link between the front and rear and the encoder only pulses the clutch pack as needed to aid in traction when auto 4wd is selected. The only ones I know of that differentiate power front to rear are the AWD's and from what I understand they basically have like a big fan clutch linking the front shaft to the rear shaft so it can slip as needed. Basically the smoke has been let out and you need to find some smoke to put back in it.

 

Are you sure about that? I thought it was the gray wire right under your tester/pointer, at least it was on mine.

 

Yes, I am sure. It may have changed between years possibly...

 

I read a post on here just the other day, the guy said in the under hood fuse panel there is a terminal labeled "Prime" he explained to connect a wire from the + side of the battery to this Prime terminal to test the fuel pump. I have been meaning to go look at mine and see what he was describing, maybe that will jog somebody else's memory on the deal.