Yes, exactly...I've said that here several times. Thixotropic is just what it is. But the mechanism of the corn header machine spins fast. Your steering gear does not.
Please look at the attached image. You might have to increase the size. The red arrow and the yellow line show where the maximum amount of lubricant can be poured before it starts dribbling out. The green arrow shows where your upper mast/worm bearing is. The box sits on your frame so the top of the pipe plug is just about right on level. This was designed so that when full with a self-leveling lubricant the lubricant would run into the top bearing and bathe it constantly...it will naturally seek that yellow line. You can also see in a correct environment the lubricant will run through the bearing, lubricate it all the way to the top and past that bearing into the mast about 1.5 inches so it will bathe the bearing from the back side also. That's it. Right there is the design the GM engineers wanted...and it is very clever. If you lose lubricant, that reservoir up in the mast means your top bearing should not run totally dry...at least until you've lost a lot of lubricant. And that's why they say to keep it topped up with a lubricant that is fluid even under cold conditions. The whole she-bang was designed with a specific and very well planned lubrication scheme. Hopefully you can see my image and hopefully this helps.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
