np241c leaking from vent tube

[tlape4965]

I have a 1990 GMC Suburban 3/4 with np241c TC and at 45mph it starts puking fluid out of the vent tube. I found a thread on here from a few years back but it is incomplete. I now about the seals and those have been replaced. If anyone can help, thanks.

 

[GMC1977]

Is it overfilled? If the input seal is bad there could be more fluid coming from the tranny into the tcase.

 

[tlape4965]

nope, not over filled and the seal is good. That's why it's driving me nuts. makes no sense.