i have a 99 cherokee sport 4x4. when it gets warmed up it shifts really hard the only way i can explain it is when your sitting on a hill and it kicks in to reverse and makes that loud noise and clanks, but this happens when i put it in drive on a flat road or when i come to a stop sign it does the normal roll back then kicks in to gear like the clutch is dropped i had it checked out by 5 different places they say nothings wrong the fluids have 5000 miles on them and are full. the u joints are all good theres normal play in the driveshaft when on the lift. let me know if you have any ideas. i plan on using some tranny cleaner the next time i change the fluid but i still have a couple mile till it needs it. i talk to some other people and they say it could be electrical but i would not have an idea where to start. thanks