Popping out of 4wd

[conan175]

I have a 2010 sierra 1500 sle, 4wd shifts and engages easily but on slippery conditions if I apply more than a little power, it clunks & spins the rear wheels.  If I baby it, the front wheels will stay engaged...  Any obvious things to check first, or am I likely tearing the t-case apart?

TIA

[richard wysong]

might be the front axle disengaging

[conan175]

Thanks, I'll check that out first

[richard wysong]

a common problem with the front axle actuator is corrosion on the threads where it screws in. The corrosion squeezes it so it can't fully extend. Take it out ,clean it up and exercise it to make sure it works while it's out. It should screw back in easily, lf you have to wrench it back in it's not clean enuff. They can get so corroded that you have to disassemble the housing and do it on the bench to get it apart