Of course, I checked the zerk first. It does indeed have 28 tpi, but it seems to be parallel,
not tapered, so 1/8-28 BSP, type G. I have not dealt with that thread before. My zerk collection
has no such fine-thread units.
I take that back: there seems to be a slight taper to the zerk threads, and it is brass.
Regardless, I drove the tractor over to my workshop the other day to get to the bottom of this.
I lifted the front end up with the loader, and the axle now pivots easily! No wobble, either.
So, now I go to test if the front zerk will take grease. It takes a couple pumps from the gun,
then stops. No more grease. So I reach over (without removing the grease gun) and the axle
is now hard to pivot again. I have to stand on the wheel to make it move, just like before. So
I push it up and down several times to see if the internal grease pressure changes, and I
can see no apparent change to the resistance of the pivot.
So then I pull off the grease gun, and I can actually see grease, under pressure, slowly squirting out
around the zerk's threads. I had not tightened the zerk back up very well, apparently, after removing
it for inspection previously.
As the pressure dropped, the axle got easy to pivot again.
So, pressurizing the front pivot grease fitting causes the front axle pivot to be resistive. Anybody ever
see that before?