TH400 Trouble

[JimmyH]

My 76 jeep Cherokee S has a new issue. I need help in diagnosing the following: TH400 trans slips in 3 rd gear only going up hill, only when hot, and spews trans oil out of the breather tube located on top of trans. Any ideas? Works and runs great any other time.

[Gambler68]

Mine does that too except instead of slipping, it keeps trying to kick down and up..sorta aggravating. Spews too.