Well I bought it used on craigslist. The cross pin broke and a small piece of the case was missing where one of the springs are. The locker had 4 sheer pin but only 4 springs. I recieved the new cross pin from chevy at a whopping $50, welded up that piece and put in my truck. I jumped in the truck put it in gear and it just runs through the teeth on that thing. It wouldnt lock. The teeth look fine. I found a sping rebuild kit for it and put it in and it still doesnt work. The only other thing I think it could be is worn out thrust washers? I called the guy and asked him about it and he swears up and down that it worked. I personally don't see why it wont.