im actually gonna bring to a mechanic this monday I think, he wants to check out my drives shafts, u joints, etc. had a problem where my hubs where staying engaged 2wd. I think a rip off mechanic switch the vacuum hoses on on 4wd actuator swicth. did some trial and error, swicth the hoses and all of a sudden, eureka, my actuator plunger was releasing. Off the top of your head, do you know if the small hole, on the top of the actuator swicth on the firewall is supposed to have vacuum sucking through it when in 2wd? mine was, thats whe it wasnt disengaging. Convinced the mechanic did that switch, for many reasons.