What to look for in an automatic transmission rebuild for a 98 gt (4r70w)

I have taken my 98 gt out and have fully dissembled everything in it. I am now going through the process of trying to figure out whats wrong (almost every gear slipped with too much acceleration). Anything I should be keen on looking for? Whats something that I should always replace when rebuilding this transmission? I am currently taking apart the direct clutch and forward and reverse clutch packs.