33/34 Steering Gears

[Mike34]

The left and middle gears are stamped "F 15" and "15" respectively. The gear on the right is stamped "03". The right is from a very original 1933 that I'm working on. I'm assuming that the 03 designates 13 to 1 ratio. And that the F 15 and 15 mean 15 to 1 ratio, therefore, they came out of a 1934. And as identified by the arrows a difference in thickness points to a difference in ratio too. I do, however, realized that there is some debate on exactly when the ratio change was made between '33 and '34.

The purpose of this post, and what I'm curious about is the copper/brass color on the 1933 gear on the right. Definitely a different material than the other two gears? Can anyone enlighten me on the materials used by Ford that would result in this color difference?
Thanks,
-Mike

 

[DavidG]

According to the engineering release files at the Benson Ford Research Center in Dearborn, the first 10,000 '33 steering gear assemblies had a 13 to 1 ratio. The steering shafts in those assemblies was 1/4" shorter than those that followed. I'd be interested to know if your shaft lengths differ.
I doubt that there is any significance attached to the colors of the worm gears as we know there were at least two outside suppliers who made the steering gear assemblies for Ford. If one copper plated its worm gears and the other did not it would not matter as long as the finished product met Ford's specifications. (Copper-plated '32-34 worm gears are not unusual.)

 

[Mike34]

Copper plated....interesting. I was thinking along those lines but because it wasn't worn off between the gears, I was doubting that thought. Thanks for that information.

I will be measuring the shafts because I'm curious about the 1/4 inch difference too. I'm documenting as I go.
But, before I can measure the shaft, I need to visit a friends shop to borrow his steering wheel puller. He' a Ford guy and has the proper puller. Not sure when I'll be able to visit given the stay at home advisory.
Thanks again,
-Mike