I am working on my sons 01 ZR2. No axle engagement. All the other components check out, vacuum switch on tc replaced, vacuum actuator pulls and holds etc. I am at my wits end trying to figure this out. It works occasionally then goes away again. My big question is, how far does the acuator actually have to pull the cable back? Disconnected the acuator pulls a good 1/2" further than with the cable attached to it. This is the only thing i haven't tried yet. The cable seems free but I wonder if it is hung up just short of engagement, not sure how far the rod on the diff needs to travel out before whatever is supposed to happen happens. Any clue? Anyone have a pic of the actuator in full pull position while attached to the cable? I'm about to burn her down!

 

Did you clean the TCCM connections?
Worked for me!

 

I looked at em, looked ok then applied dielectric grease to the plug. I suppose i can pull it off and clean em but i doubt thats the problem, nothing is ever that simple for me. Lol. Thanks!

 

After replacing vac switch, cable and checking everything else I was faced with the inevitable conclusion that the carrier gear on the ps axle had to be chewed up. Pulled the axle and sure enough, it was wasted. Ordered a kit from napa. What a f'ed up system this is on an otherwise great line of trucks. To help others out my condition was not unique but my symptoms drove me nuts. I was able to engage 4x4 occasionally by removing the 3 bolts on the cable housing and pulling extremely hard on the cable while truck was on stands and rolling in drive. Problem was after applying load to it while driving it would bang back out. The vac acuator did not have the power to engage because of the gear damage. Thanks for reading. TK

 

can you buy just that gear part, never seen one of those get chewed up like that before


ive actually fixed a few s10s that way. water seems to get in there sometimes and messes it all up