98 dodge durango transmission

My dodge durango transmission when start will shift into gear but appears to slip till it starts to coast .have to stop turn off ignition then it will go but doesnt go very fast then it will slip and have to do it all over again turning it off and back on for it to go.i checked the fluids and it. Appears to be burnt is the transmission no good can any body answer this_??thanks

I can fixit if i can find out the problem it is an option ill take into consideration