Go switch your hubs to maual then back to auto a few times. If they are hard to turn then its a bad hub. My dads were not even able to turn so thats how we knew. If they turn fine try putting it back in 4 hi and 4 lo by using neatral or whatever you have to do drive a little bit stop put it in neautral then back to 2 wheel...back up for a ways maybe 100 ft or so see if that helps. Also turn on your heat and see if you can get it to blow out all vents (floor dash and defrosters) if it doesnt come out all then it may be the vaccum actuator for the shift on the fly.