I have a 1986 f250 6.9 with a c6 transmission. When I shift in to 4 high I hear a grinding sound coming from the transfer case. The front tires don't spin in 4 high either. When I shift into 4 low I hear the same grinding sound just not as loud. The front tires spin just not very fast in 4 low. With this problem do i need a new transfer case, or just a rebuild kit or is it somthing else in the transfer case that I can buy so I don't have to buy a new transfer case. Thanks for your help.

 

Sounds like the Planetary is toast ..

I have a BW1345 if you need one .. Pm me