i used to have to hit mine with a rock to get them to turn on my 89 sidekick

although freezing wasnt the problem
i pulled the bad side off, cleaned it up a little bit and sprayed wd40 in there... PROBABLY not the right way to do it, but it worked out for me
thats my tip, and in my opinion auto hubs suck, and so do pushbutton 4wds... manual stuff re-assures u that your t-case IS in 4wd, and that it WILL be transferred to the front wheels... plus u gotta be pretty lazy to need the auto stuff
too many hassles
ive typed enough though
Andrew