MY 97 sits with the front axle engaged as I type this. The 2wd light was glaring brightly when I left it.

Let me clarify something - I just started driving it yesterday - a trip to the alignment shop. New-to-me truck I've worked on for three weeks to make road worthy. It didn't do this on the trip home, except for just a little bit. I've fixed all my vacuum leaks....


What I have done:
checked the actuator. Good.
changed cable to one that works. Existing was near froze - engaged.
diff piston worked fine. After cable install I manually checked function and it was fine (wheel turn - DS not)
Running....front axle is engaged regardless. I can try making the switch in park or neutral sitting still and it makes no difference.

It does look like someone has had the tranny out at some point. I am thinking maybe the vacuum lines for the controller got swapped.

Perhaps this would explain why I found one line up top unconnected and the cable was frozen due to non-use. It got messed up and to keep the front axle disengaged they just undid the vacuum lines. Its a theory.

So....what do I check from here....?

I am going to unplug the vacuum from the actuator at lunch and see if the axle disengages. If it does - I'm thinking its clearly a vacuum port thing. If it doesn't....I still have a cable or piston problem.

The cable I swapped in came off my bent-frame 2000 Jimmy and I it worked smooth. I still oiled it more and worked it just to be sure.

Help. I want this thing to not drag down my mileage and I don't want to increase wear and tear.

Thanks

 

Check the Vacuum Switch on the Transfer Case. It is located near the front of the case and has three vacuum hoses coming to it. If it is bad, it'll have to be replaced. It is onyl like a $20 part that simply screws into the case.

 

Not the problem. Still engaged. Must be mechanical.

The cable can't be pushed in enough for me to hear the 'click' I heard last night. Maybe I have the cable in a bind or something else if stopping it. Will look later.