94 b4000 4x4 trouble

[homers_94mazda]

hello i have a 94 b4000 and it runs good drives nice but my 4x4 dont work the button on the dash works the transfer case is working i think i have tracked it down to the front diff i have manual hubs front drive shaft is turning but my front tires do not turn can anyone help me is it as simple as just buying new hubs and changing them out ?
hoping someone has had the same problem in the past and can help me thank you for you time

[Tallon T]

I have a 94 b4000 4x4 also. The 4x4 button would light up but the front tires would not spin this is when it still had electronic hubs when i swapped them to man's it worked fine and has worked fine for 140k. So it may be that simple but it rarely is