I have a 2000 f250 5.4L with a Dana 50 axle. One of my stock manual locking hubs fell out and i need to replace it. I bought the mile marker manual locking hubs with the 30 spline. The splines for the locking hub and the axle fit. But the locking hub outer diameter is smaller than the splines on the hub itself. Ive been looking around everywhere and i can seem to find anything on this. any ideas

 

That's strange, can you post a pic of the issue, my thought is you have the wrong hubs..

 

I bought those exact same hubs and thought the same thing. I even returned a set of those hubs and bought another only to find out that they were exactly the same. If it is like mine they WILL actually go in. You may have to keep turning it until it will slide in but I eventually got mine in and they work great. Half the price of the Warns and they are holding up just as well.