IHC 9-A Disc Harrow bushings

I'm rebuilding this old harrow. It had lots of wear and abuse during it's youth. But now everything is taken apart and ready to reassemble.
Each disc assembly has 6 discs mounted on a 7/8" square shaft with three spacers and two spindles. The spindles fit in the split cast iron bushings mounted to the harrow frame.
Found a lot of hardened dirt and grease in the iron bushing grooves.Once cleaned out, the spindles which rotate inside these bushings are incredibly loose yet don't show that much wear.
Were there some kind of replaceable liners which fit inside the iron bushings? Like a babbit or bronze bearing liner? I see no evidence of anything like that but can't imagine that it's designed with 1/8" clearance between bearing surfaces. And nothing is sealed so the grease will just push out.

Yes that is the way things were designed. The amount of grease that was used was designed to push out any dirt. The bearings are what they call whiteiron (not a metal guy so do not know the difference in whit iron and other iron), You greased then about every 4 hours and used a full gun of grease about every time. What you are calling spacers are actually called spools with the ones in the bearing housing just being bearing spools. What you are refering to as disks are called blades and that disk, the complete unit, would have had 16" blades and probably could have been bought with 18" blades but 16" were cheaper and people at that time were mistakenly thinking that the 16" did a better cutting job and pulled easier, actually opposite is true. If that 16" blade got down to 15.5" it was wore out and should have been replaced but most were used untill the blades were down to 12" and instead of buying new blades the farmer would go over the field an extra time or 2 to be able to get it in shap for planting not realizing he would by replacing those small blades with 18" ones he would have reduced his fuel usage by more than enough to pay for the blades without realizene he could have a lot more time for other things. And with the bigger blades cutting passes over field he would also cut his grease usage and the smaller blades having to turn more times took more grease than the larger blades. You get the bearings too tight the dirt that does get in and at that time nobody ever thought about a sealed bearing the grease could not push out the dirt and grind up the gearing, think small stone, grain of sand. What you are doing you should by new 18" blades in 18 guage and where Shoup is said to bea good place for blades they do not supply a blade to properly fit your disk. A place down south that I cannot think of the name is best place to find something.

Thanks for the insight. Actually this implement was rescued from the scrap pile and I'm re-configuring it into a single action harrow, suitable for my small plot. Only about half the parts were worth saving anyway.
The front blades measure between 15"-16 1/2". The rear blades measure between 16 1/4" - 17 1/2". So I suspect they were all 18" originally. I'll use the best of the lot.
White cast iron is produced by chilling part of the mold after casting to create a surface layer high in iron carbide which is harder than grey cast iron and is better suited as a wear surface. Nowadays, chromium is sometimes added for wear resistance but I doubt if that was practiced way back when these casting were produced.
Next step after assembly will be to figure out how to lift it with my 3PH.