how do you use the 4x4 on a chevy suburban?

[Natasha]

i never used it before. my vehicle is not moving when i put it in any gear. how do i use the 4 x4 to see if my rear end is locked up?

i already know i need a rear end but im trying to see if its locked up or just dead.
the rear end has been bad for 5 days now, and it was still being driven. yesterday morning when i went home, the truck would not shift in any gear. the drive shift was making a very loud noise and wont move at all. my u joints are good also.
the 4x4 is in the floor.

 

[mikeysuburban]

All you do is put the trcuk in nuetral pull the 4x4 to 4 low then shift into drive and drive a little ou should see your 4x4 diagram kick in.