Got a wear groove on the yoke shaft? Tranny vent is a rubber mushroom on the top, on the shifter plate, I think.

The bushing has a spiral groove which is supposed to carry seepage back to the tcase direction in forward travel. I'd check it for a dam.

The yoke do have a tendency to leak out the plug hole. I'd look at some rtv to reseal it.

Not responsible for advice not taken...