Locking hub won't go into hub?!?

[swanthog]

I bought a new Warn locking for my 1980 3/4 ton and it won't go into the hub. I double checked that the correct Warn was purchased and should fit but it's not going in there. No way.

The outside diameter of the Warn is slightly larger than the hub opening. The outer and inner splines line up and it will slide in until the larger diameter part of the Warn is reached.

Has anyway encountered this before? Could the hub be warped to the point that the locker no longer fits? It doesn't appear to be damaged.
Is it possible that someone put a different year-range hub that requires a different Warn locker?

Thanks,
Lawrence F.