Chevrolet Repair: 4x4, auto hubs, frt

Question
HI i have a 2007 chev vortec max that wont go in 4x4 the light comes on i can hear it go in,and the 4x4 shaft is locked in but the front tires wont spin just the back traction control is off????? Can you help??

Answer
Derek
Is there any noise in the frt when you try to move it? If the frt is hooking up and not spinning it's usually indicative of a failure in the plantary gears.
The only way to tell is get it up on the lift and have someone engage the frt axle and see if it spins. Do you have auto hubs or maunal hubs make sure your hubs are locking up