GMC Repair: 2000 sierra rear end, spider gears, rear brakes

Question
the diff is not releasing every time. everything seems to be in good shape no excessive wear no big peices of metal.Do you think it is the springs in the locker? i am not sure it has me puzzled.-------------------------
Followup To
Question -
when I turn sharp,moving forward or reverse the rear tires drag.I have eliminated the brakes from causing this.it has to be in rear end.
Answer -
What exactly have you done to eliminate the rear brakes?

This vehicle is equipped with hat drum rotors, which means that the emergency brake is in a drum inside the rotor. This may be where the problem is also.

What do you mean by "drag", does it leave a solid streak like the tire is locked up, and is it both sides.

You could also have a problem in the differential if it is a locking unit it may not be releasing. To check for this raise the rear axle and spin one side your hands while holding the other, it should not spin both sides immediately. If it does you should remove the differential cover and inspect for large pieces of metal which would indicate a failure, or other noticable damage.  

Answer
More than likely that is your problem if it is not releasing. I wish I could look at it myself, but you may want to remove the carrier and inspect it. You can only replace the gears, i.e, ring and spider gears, or the carrier itself, but not just the springs. It is possible that the locking mechanism is failing and it does make sense that it would cause you tires to drag on turns.