Be sure the dipstick is reading correctly and you're not overfilling it. The FULL mark on the dipstick should be about 1/4" above the ledge where the dipstick tube enters the case.
I agree with john, few years back I had a transmission shop re-build the A-518 that's in my 91 short bed 4x4 dodge truck and they decided to give me a new dip stick tube that went behind the engine instead of to the side how they normally did them.
I had the same issue, tranny fluid pouring out of the front, took the truck back cause it was under warranty.
The owner him self got involved and pulled the transmission and I called him and he said i tore the entire thing down and I have no idea why it was leaking everything is solid, and that night while he was laying in bed he remembered the dip stick tube they had swapped inn and bells went off and sure enough they had over filled it by about 2-3 qts and every time I would hit the highway it would come out.
So make sure your dip stick level is right before tearing it back out.
