When I try to engage the 4wd it sounds like it wants to engage but no 4x4 and after I disengaged it makes a whining noise somewhere in the rear end I think. Its sounds like something is grinding if that makes any sense. Need some advice, thanks

 

I've herd of the vaccume lines that engage the front hubs sometimes go bad..... Not sure about the whinning noise tho

 

The vacuum keep the 4x4 from being engaged. If there's no vacuum then 4x4 is engaged by default. You may want to check the IWE solenoid lines for water in the lines that's frozen.