From the beginning of production in 1928 and into the 1929 production year, our Model A's came with what is known as the "Seven-Tooth" steering boxes. During the 1929 production, Ford switched to the Two-Tooth steering box, thought to be more robust, highly adjustable and otherwise better than the original seven-tooth box. The two-tooth box continued on until production ended in the 1931 model year, although it carried on from there in other year Fords.
The reasoning for the change is both up for discussion and lost to history. The seven-tooth box had an 11:1 steering ratio while the two-tooth improved it to 13:1, making it easier to steer and maneuver. The seven-tooth offered little room to adjust for normal wear, requiring shims or even bending linkages to make up for wear. The two-tooth offers four distinct external adjustments to compensate for age and wear. Also the seven-tooth was notorious for leaking oil, but the redesigned two-tooth housing was better at preventing leaks.
Many Model A Steering experts have told us that rebuilding a seven-tooth steering box yields little or no real improvement in steering accuracy or effort. The parts to rebuild the seven-tooth box are more expensive, and the effort needed to rebuild a seven-tooth box is somewhat prohibitive for the amateur.
For this reason we do not carry or sell parts for rebuilding a seven-tooth steering box.
SO WHAT ARE WE TO DO?
If you are restoring a fine point Model A for show, rebuilding the stock seven-tooth steering box is probably where you will go. Parts are available from the experts that will be doing this kind of restoration. But what if you have a "driver" that you just want to enjoy?
The most common answer is to find a two-tooth box, column and steering wheel, rebuild it and replace the seven-tooth with your newly-rebuilt two-tooth box.
There are columns available on Ebay, at swap meets or in a club member's shed that will work as a good starting point. Take it apart, order the appropriate 43" or 44" steering shaft complete kit, and once it is rebuilt, painted and beautiful, install and adjust it to your taste. Yes, it takes more effort and more expense, but those who have done it in the past suggest that this is the best course of action.
Our "steering guru" in our club had a 1928 Tudor that had a seven-tooth box that needed some help. He obtained the correct new parts, rebuilt it, and installed it back in the car.
No noticeable difference.
In a couple of months, he obtained a two-tooth column and rebuilt it, replacing the seven-tooth column with the rebuilt two-tooth. Huge difference and adjusted perfectly.
Just something to consider with your own Model A. Our opinion from conversations with veteran Model A'ers from all over.