Lone voice in the wilderness - on my '87 FJ60 and '78 FJ40, I removed the vent cap on the xfer case, which prevented it from pressurizing and pushing the oil into the transmission, and never had this problem again.
Both trucks suffered the 'empty xfer/overfilled transmission' problem at one time or another. However, I have no beef with the hose between the two fill plugs - it's benign, effective and cheap.
Colo Springs, CO
'78 FJ40, '89 FJ62, '98 4Runner