i bought my 99 f250 not too long ago and it pretty much makes it through except the 4x4 doesnt work and every time i get stuck i start to look and check it out and end up giving up but now i got stuck again in a stupid spot for an hour which wouldnt have happend if it just worked anyway heres my problem.....

no 4x4
*with the truck running in park the front drive shaft spins by hand freely
*i turn on the 4x4 switch (i have no locking hubs) the way the owners manual says and put it into park
*with e the 4x4 switch on the axel now doesnt spin, so the 4x4 switch is telling the motor to engage the driveshaft and the drive shaft is locking in 4x4 but i have no 4x4

my guess is that when it spun freely in park with the 4x4 off the transfer cash didnt lock it obviously (which it shouldnt) but when i spun the front drive shaft by hand in park the front tires should have tried to spin right?

so to me it seems i have a problem in my front axel, maybe a stripped gear? but i think a stripped gear would make nasty sounds while trying to drive?? or is there a way the front axel locks in besides at the transfer case? i just need other possable ideas because so far i dont have a solution