Sounds like a bad switch. Or a plug in the lines somewhere.

Pull the switch out of the t-case, hook up the lines, supply vacuum, either with a pump, or, start the engine.... and manually operate the switch, see what ya get.

 

Ok ill try this today. Thanks

 

What is that metal ball supposed to do. How does that switch really work. Thanks

 

Ok, I got it fixed and these were the problems.

1.) As I was giving supply the swtich would work properly, just the rubber connecter that goes on the switch would not hold tight and leak all the vacuum.

2.) Now that I got vacuum I went to the shifter motor assembly. That connector was also rip so fixed that with new single fittings.

3.) Still would not work so took off the plate and notice it wouldn't shift over. I took it off completely to see that it had a few holes the the metal housing which leaked vacuum for the 4x4 side. Freed it all up, cleaned the hell out it, and did jb weld on the tiny holes. Let it cure for 4 hours.

4.) Put it back and closed it up and changed the gear oil in and filled with new oil.

Now it works perfectly. Thanks too all that helped.