1991 GMC sierra 2500 4x4 5.7 4x4 problems?

[bub350]

lock it in and it takes a few min to lock in does the same when take if out of 4x4

 

[Molson02536]

lock it in and it takes a few min to lock in does the same when take if out of 4x4

The problem is your front axle locking actuator has gone bad and will need to be replaced. Look in the suburban forum, I helpe out a few guys in there with similar problems and the 4wd system are the same. Good luck, all the information is there and the upgraded part needed to fix yor problem.