In my 89 f150 xlt lariat it won't shift into anything but four high and even then I can have the truck in 1st gear and in 4 high but it'll stay in neutral and tires won't spin, even with the hubs locked, but as soon as I shift out of 4 high its fine, I tried putting the truck in neutral and holding down the clutch but it won't shift into anything other then 4 high, any ideas on what it might be?

 

Sounds like a bad shift fork in the transfer case....

 

Yeah, transfer case problem, if that's it it's not cheap unless you have a junk yard close by and a spare weekend or 2.