I have an extra steering box from a 56 F600. It is larger than the one from my 56 F100. What model was the breakover point to the larger size, or maybe a better question would be " What other models would this gearbox fit ? " I took it apart and it is in very good condition, very little wear on the sector or worm gear. May rebuild and offer for sale if it has a wide usage factor.

 

In the earlier Bonus Built era the F-1 through F-3 used the same box, F-4 and up used the larger box. I don't know if that followed through to the later years.

 

They workgreat in the f100s for easy steering. I would install it and see how easy it is. I have done it to 2 of my f100s and it fits great.....Bill

 

That's what I was told about the bigger boxes for the '48-52 models. The splined shaft is larger so you'd have to use the pitman arm from the larger trucks, at least on the older models.

 

Walford / bobj49f2,
I thought it might mount in an F100 model but unless i looked
at it wrong it looked as if the mounting hole were different.
Did you redrill them? Will the pitman arm from my F600 transition
to the drag link on the F100 or does it need some modification also.
What makes them work better/easier in smaller trucks?
Is it because they are larger and have a mechanical
advantage? or is the actual gear ratio different?

 

I was told the gearing makes it easier to steer. With the bigger trucks you have a lot more truck to manuver. In the earlier models you have to enlarge the shaft hole, that's only reason I haven't done it with my F-2, I have a couple of the larger boxes but I just don't want to hack into my frame.