Corn head grease, CV joint grease, or any 00 or 000 grade grease is thicker than actual steering box grease. It works just as well but takes a lot longer to leak out. You can mix chassis grease 50-50 with gear lube, or run straight 140 gear lube, or any other combination of lubes as long as it flows. It all leaks over time, the thicker stuff takes longer. Ever see a dry steering box?
I've been using JD Corn head grease for more then 15 years, the gear box is damp and has a drip on it but never makes a mess on the floor, it still steers just as easy as when I put it together. Watch the video from JD explaining their grease.
