compatibility of transmission need help

[ndavis426]

I have a 99 explorer I replaced the transmission with one from a 98 still don't work right....is there a difference between the sohc and ohv explorer or is there some others non compatable issue that I'm not seeing

 

[BrooklynBay]

Maybe the replacement transmission was defective or there could be an issue with a sensor on the engine, exhaust or wiring. What kind of issue are you experiencing? Did you install a used transmission?