help my tranny

hi new here, my first post,awesome site! well here goes,i have a stock 85 xj,small block gm 2.8l v6, trans is tourqueflight 904 3 speed automatic. i live in canada,and during the winter(present)when i first start driving,the trans shifts into gear nice under inital load.while driving,my rpm gauge goes up to 3000 before it changes,and gives a violent kick when it happens.after 15 km this problem stops, and a new one occurs.when i park,and i move the shifter from d to p, there is a loud clunk when i pass through r.also,if i drive it again within 1 hour,i put the jeep into reverse and there is a loud bang,with a violent movement all gears do this.what the hell is wrong here!here is some more info, rear differential is weeping at drive shaft,i installed new shocks,have new tires,rpm is at 750 when putting into gear,t case makes a weird noise when in 4 lo-hi,some times shifter will not go into park,and i also noticed that the rear bearing seals are leaking(oil on back wheels)i hope i wrote this right, thanks for the help guys! dave,new jeep maniac