I see that parts dealers provide the sun and planetary gears for the steering column gear set - what's the incidence of wear in the brass case ring gear ? Do the steel gears in this arrangement tend to wear out, but not the brass ring gear ?
The case does, oversize gear kits try to compensate for it.
The parts book says you can get a new case from your Ford dealer for $1.50.
Ford used gears for 4:1 ratio 09-24. 1925-27 the gears were changed to 5:1 for easier steering with the then new 21" balloon tires. The odd thing is that the 5:1 gears and steering shaft can be fitted in most older worn 4:1 cases, and then sometimes tighten it up. The repro 5:1 parts supplied by the vendors may need some extra fitting with Timesaver lapping compound.
The longer pin intended to be a stop into a groove in the 20's brass case has to be shortened if used in a teens brass steering case.
5:1 is preferred by many if driving faster than they did back on the old roads.