[redmodelt]

I would think of two things, some 600w's from my experience foam real bad (I have some of this type in my Warford on my Model T) or it is over filled. Where the shift ball rides is not much of a vent. The ball on the lever rides in a machined area.

I would check the lube level before a drive to see how full the box is and after a drive for foaming. If the lube is wanting to come out the filler hole on the side when you open it before a drive, it's too full and I would suggest lowering the level to about the bottom of the thread.