I have a ’93 Explorer with the 4.0 liter V-6, automatic (not sure which one), manual 4x4 front hubs that has 150,000 miles on it. On very short trips everything works fine but after about 20 miles it leaks tranny fluid from the vent at the bottom of the bell housing. When I put it in Park, it is a slow drip but in Drive it pours out. Does anyone know what might be causing this? Is it something I should be able to fix myself? I have basic mechanical skills, could drop the transfer case and tranny if required but no skills with automatic tranny internals.