Why would a transmission on 96 ford explorer just stop working out of the blue

Well i can tell u from experience as aobile mechanic and an owner of a 96 explorer 4.0 ohv sporttrac the 4r44e5 trannies are horrible! Slipping ,blowing selinoids,sensors, fuses,amd more i feel like ots a solid truck built around this terrible transmission where im impressed with tbis 4liter v6 ohv motor and wish that i had a betyer 4 wheel drive system at 203000 milesand a blown head gasket (leaking water into all 3 cylinders on the passenger side)a major exhaust. Leak and a dying tranny shes still got the power and still has pulled through. So my suggestion is find a different tranny and use it any thing but the 4r44e5