1998 Ford Explorer transmission.

That depends on a few things, if the engine from the 2000 Explorer is the same as the one in the 1998 model, it should fit perfectly fine. If the 2000 model uses a V6 but the 1998 model is a V6, it won't fit. Also, make sure the transmission is the same on both models. If the 2000 model uses a manual but the 1998 model is automatic, then it won't work without modifications. Lastly, Ford may offer different transmissions for different model years. The 2000 model may use 5-speed instead of a 4-speed in the 98 model. To cut to the chase, make sure the transmission is the exact same before purchasing it.

How do you know if they are the same transmission ?