88 Bronco II 4WD Question

[alikazaam]

Lately my '88 Bronco II has started popping out of 4WD while I'm driving. I have no problem shifting into 4WD, but while I'm driving it pops out. Why is this happening? What can I do about it?

 

[Broncosaurus!]

ask in the Bronco II forum for better luck.