On the top of the trans there is a small rubber tube that is a "breater" for the trans, check there. Also I think you need to check the fluid level in the trans. I know it is strange, but recently doing a trans service I removed the fill plug and got drenched with fluid. The previous tech WAY over filled it. It is a spill over fill. So when you fill it, you should let it drain off, until it stops.
Conversely, if it is low on fluid check your axle seals, and you may wish to remove the shift linkage gray plastic cover. The shift shafts each have a seal. The entire trans only has 5 seals, plus the o-ring for the oil filter screen in the trans, yes there is a filter since the trans does have its own oil pump system.
HTH,
LarryB