Ok I have a 1998 cherokee 4.0l auto with a bad tranny will a transmission from a 1994 cherokee mount right up and have same wiring and everything

Generally yes. Just establish the model of your current tranny and find the same. It's prolly an AW4 that was pretty common on automatic XJs.

the only thing from my experience is that they have different control modules and different ways of controlling the solenoids. i tried the wiring trick to manually cntrl my solenoids on my 98 like you can on a 94 and well it didn't work. so i'm pretty sure the electronics aren't the same. hope this helps.