Only two things come to mind 1-loose convertor generating way too much heat . 2-G.M. had a problem with autos puking fluid out several years ago and redid dipstick and tube to a style where dipstick has a seal on cap end that swells and seals tube when lever is flipped down. ask for one for a 86 c-10 (1/2 ton pu.) with a mv4 tranny and you will see what I mean. be sure to get trans to tube seal as well as I think they are revamped too.