so i know my 4x4 is working in drive... but it seems to not work in reverse... i dont understand.. lol.. i can drive straight threw deep snow no prob... but when i put it in reverse... neither one of my front wheels will spin just my back ones... any ideas? it extremly odd and frustrating since i live in wisconsin. lol thanks... also yes im sure its in 4x4 and i have vacuum. Its a 98 blazer zr2 with a g80 if any of that matters

 

3 or 4 button 4WD switch on the dash?

Transmission gear position does not affect 4WD operation. It can not perform a mode shift, or change the vacuum to the axle actuator. If 4WD is working in drive, it's working in reverse. If 4WD is not working in reverse, it's not working in drive either.

 

Its a three button... I can never seem to get the drivers side front tire to spin in reverse. Cant tell if the passenger side is or.not because well.. I'm always alone. Lol. I can def tell I have 4x4 though. I can try to drive up a packed snow covered hill with it in two wheel and she just spins and slowly climbs sideways... But in 4x4 it just goes straight up no spinning

 

There ya go, there's your answer. It's working. Try backing up the hill in 2WD, then 4WD It'll do the same thing.