2001 dodge ram 4x4

hey everyone i just bought a 2001 dodge 4x4 with a 5.9 off road package and i was woundering if anyone has had any experince with these trannys. when i first bought the truck i test drove it and sometimes it wouldnt go into drive but i bought it anyways cause i love these trucks and i no from 94 from 2001 they had problems with them. so i took it to my shop and i checked the fluid and it was low so i added some and i kinda fixed the prob with it not goin into drive but it still shifts hard and it squeals like a pig when you get on it so just for a quick and non $$ fix i was goin to do a tranny service and put in a bottle of lucas but wanted to get some ideas first what do you guys think?

thanks mopar 426