A stock Model A steering box looks right at home in a 40's or early 50's hotrod. Preferring the stiff feel of manual steering big block Mustangs and Corvettes to cushy power steering, I opted to keep the original Gemmer two-tooth box when I converted my Model A to a flathead V8. The box was recently rebuilt, and having driven the car as a stock Model A, I was more than happy with the ease and feel of the steering. I can’t remember ever seeing a thread on how to do this and thought others might be interested in the modifications I made to the steering box to accommodate the new engine. Introduced in mid 1929, the two-tooth Gemmer steering box is easily identified by the prominent fill plug and adjusting screw on the top of the main casting. Much improved compared to the earlier Model A seven-tooth box, rebuild parts are widely available, steering effort is greatly reduced, and unlike the earlier box, the later box is 4-way adjustable for wear. It is essentially the same design that Ford used until they brought out the recirculating-bearing steering box in the late 1930’s. As is commonly the problem when upgrading the Model A for the later F1 steering box, the stock Model A box needed to be moved upward, rearward or outboard to accommodate the wider V8 motor. As I had already wrapped up the front axle of the car, relocating the box upward or rearward would have caused problems with the front end geometry/bumpsteer and required a custom drag link. I was not using running boards which would have hidden an ugly boxed frame mount, and I was concerned about the loss in strength to the already week Model A frame. Shortening the sector shaft housing to move the box outward gave a clean look on an open engine car. At first I was kind of squeamish about the idea of tampering with the steering box mount, but after some thought, I realized the beauty of this approach. The sector shaft is captured in the frame by the steering box on the inside and the pitman arm on the outside. If something breaks, the worst case will be mushy steering, much better than a catastrophic steering loss if a welded bracket lets loose. After careful measurement, I had my machinist removed an inch from the sector housing. He match-marked the housing and turned a step in the two-eared frame mount end and a receiver in the rectangular base that bolts to the body of the steering box, leaving a 1 3/32” bearing in the frame mount and a 1 ¼” bearing in the rectangular base. The frame mount end of the housing was machined for a lip seal (available from any of the Model A resto vendors) and ¼” of the rectangular base bearing was removed at the outboard cut to provide a path for lubrication. The end result was 1" long inboard and outboard bearings separated by a 1/4" lubrication gap. The halves of the modified Model A sector housing were welded once I double checked the fit-up. The rest of the mods were pretty simple. I machined the ribs from the rear lower edge of the Edelbrock head to clear the steering column, made a 4” by ¼” notch in the top flange of the frame rail to accommodate the shortened sector housing, dimpled the flange to clear the steering box adjusting nut, and trimmed about an inch from the left edge of the firewall cutout to clear the steering column. I kept the stock gravity feed tank which ruled out a lot of options for supporting the column so I used one of the later brackets that bolts to the upper dash available from any of the Model A resto vendors. With the upgrades to the suspension, steering and brakes for the new motor. I also opted for a shortened Model A pitman arm to reduce steering effort with the 16” steelie wheels. Mike’s Affordable in Georgia has new 1” shortened arms for about $70. Though not a dime a dozen, the stock Model A Gemmer box is a traditional, compact and low cost alternative to the harder to find and more expensive F1 and F100 boxes. Don't rule it out when considering options for your build.
Very clean!! Much better than the traditional welded box, usually constructed from 1/2 lb. of steel and 3 lbs. of welding rod... For those using this box, here's a good article on the 2 toother and how to refit the gears. Original gears good enough to redo will give better results and probably require less fitting than the repro stuff: http://www.abarnyard.com/workshop/steering.htm Same basic tech applies to '32-36 boxes generally, though all the parts changed multiple times through this period.
Good Stuff, thanks! I have a 31 Vicky with a stock box but my motor is off set because of the box.. It's just tacked (motor mounts) so I can shorten the box/arm and slide her over.. My question is the sector shaft ?? what is done to that? thanks John
Glad to help! Folks don't usually do anything to the sector shaft when they shorten the housing on an F1 box, just let it stick out a bit further. That should work fine here as well. I was thinking I might sacrfice another sector housing, cut it to length and mount it on the outboard side of the framerail for extra support.
Looks pretty clean. I've got steering to figure out pretty soon. Is there enough room for the motor to move around with out smacking the column, and to get the lower corner head nuts on? thanks, Gary
jackanddeuces wrote: Ill bet you have a good machinist Yeah, Jim Geiger, how'd you guess The steering box clears the lower head bolts/acorn nuts but the heads need to be installed on the engine before you put in the box. As you can see in the pictures, it is a tight fit at the lower rear corner of the head. I could have gotten more room by dimpling the steering column tube, but it does clear and will make it's own room as required to accomodate engine movement.
A mate just did a RH conversion using an Aussie RH box. With stock heads and a small simple in the column it fit fine. The single biggest improvement he made was shortening the pitman arm 1 1/2 inches. He had it all fairly tight in the adjustments and no play at all ( maybe a little stiff for my liking but better than I have ever felt an early box) but with the short pitman arm it feels like power steer and is an absolute pleasure to drive. Best steering early ford I have driven - period!
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