I am assuming the transmission is garbage but it has me curious. I bought a 98 f150 4x4 4.6l knowing it had no reverse or neutral. While driving back to my house a very loud pop occurred. Now no forward gears but I do have reverse and neutral. I am assuming it is some major issue inside the transmission requiring it to still be replaced but wanted to check with someone who knows more about transmissions then I do.

 

The forward clutch failed and welded itself together. This will cause drive in neutral and no reverse. The bang were the self welding breaking, and now there is no forward clutch. This will let reverse and neutral work again.