steering box mounting frame holes

Yes, the passenger side did not have slotted holes if I recall correctly.
Any looseness in the mounting would wallow out the holes in the frame.
 
I have a 30 Tudor that has the same issue. Prior to disassembly, it looked like the sector housing bushings were totally shot. 1/8" movement visible in the sector shaft when steering. Turns out the bushings were only light medium wear, but the travel of the housing in the bolt holes was excessive. The upper hole is visibly elongated, the lower one less so.

Also, the bolts had crushed threads in the area where they passed through the frame, this effectively reduced their diameter and allowed even more play. The replacement bolts don't have a very long shank - the unthreaded portion. Same issue could develop.

So where to find a longer shank bolt that is preferably drilled for the castle nut? That's a tall order at your hardware store, but an off the shelf item for aircraft, they are a heavy consumer of safety wire and drilled bolts. Sure enough, an AN7-12 bolt is just what you want. They are easily ordered at Aircraft Spruce.

So here's 2 questions. For those of you that have undamaged holes in the frame, how much play was there when you inserted the sector housing bolts? The holes in my frame for the shock mounts are very tight on these bolts, but the steering sector holes have slight movement, say 1/64" on the fresh bolt shanks.

And if you had some slight movement as opposed to a tight fit when you assembled your steering, did a tight grip on those bolts eliminate all movement of the sector housing on the frame?

I'm thinking of adding a washer under the castle nut to spread the load and add to the grip.
 
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First photo, left to right

Original bolt from car, note the shank wear and crushed threads.
New bolt from Model A parts store.
New AN7-12 bolt, Cad plated. The bolt is a fat 1/8" longer, I don't expect that to be a problem.

Second photo. Standard replacement bolt against sector housing. Note how the shank is only long enough for the sector housing, not the frame.

Third photo. AN7-12 bolt, showing the longer shank that will bear on the frame and offer far better strength and durability.
 

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Brentwood Bob said:
Shank of the aircraft bolt appears to be a little long. Let us know how it assembles.
Click to expand...

I agree. Maybe check the NAS bolt dimensions - there may be one with a closer shank length that is needed than the AN bolts. I am not sure of the sector shaft flange thickness but the AN7-10 bolt has a 7/16"shank. (1/8" than shorter than the AN7-11)

John
 
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You guys motivated me to do a test fit on just the sector housing, shaft, and pitman arm. With the AN7-12 bolt, I was surprised to see how little clearance there was. Torqued down it will likely bind or even hit hard. So back on the internet. Aircraft Spruce didn't have the AN7-11 bolt, (Which is why I got the next size up thinking it wouldn't matter) but Skybolt does.

Taking up the small excess length with washers on the head end is rife with problems too as there isn't enough shoulder space for even narrow washers to fit. If you grind a flat edge to fit you will play safe cracker x2 dialing all the flat edges to line up as you fiddle blind in the frame channel. Sigh. This is not a place where "Working on the Model A is easy".
 
OK, post assembly:

I finally got several AN7-11 bolts, for some reason several suppliers are out of them. They have the longer shank, and the total length is barely 1/16" longer than stock. I added a washer to spread the load. Even loose you could see this was a far better and tighter fit.

No interference on the pitman arm with that slightly longer length. In a perfect world I'd grind down that 1/16th, bevel and chase the threads.

Because there are currently no sector shafts in the pipeline I reassembled with the old sector which had some minor wear, on new needle bearings. Adjusted for shaft play and sector mesh.

When I started I had about 60 degrees of play, or about 9 inches at the rim. Luckily my wheels are really well balanced, as it still tracked quite well.

Post repair I have (sitting in the garage, haven't driven it yet, just snowed 3 inches here) about 1 1/4 inch of play. Huge improvement. So the plan is to drive it and see how it settles in, re-adjust as needed, and go from there.
 
I know most of you will not agree with what I have to say but here goes anyway . The holes in the frame are not designed to suit different bodies the elongation is designed to accept very slight movement . I was taught in Mr de Beers garage in Camps Bay South Africa NEVER tighten the steering column hard up to the frame . Over rough roads the frame is very flexible and when it twists and the column is solidly bolted to the frame a lot of stress is transmitted to the column and gas tank bracket which can cause the column tube to crack and the gas tank to leak . I tighten up hard and then back off just a tad then insert the split pin . I do put a bit of copperslip between the box and frame . I have never yet have had to retighten the box bolts but I stay away from rough roads !!! The holes for the A400 ,de luxe phaeton etc are adjusted to suit the dropped column .

John in very windy rain as well Suffolk County England .
 
Just drove it for the first time. I'd say the play is even better than I thought, it's under an inch. And this is on the old sector shaft and worm, with a new needle bearing sector housing, the above mentioned better housing to frame bolts, and a new pitman arm.

On the sector mesh adjustment, it's pretty darn good when centered, and there's just a smidge of resistance when turning wide. I'll take the trade-off, unless this is going to cause accelerated wear.

I'd say I had a few thousands pocketed/dimpled on the sector teeth, and just minimally noticeable like (.002) on one side of the sector shaft. While it would have been nice to get new parts, there's no telling when new sector shafts will be back available, and this looks like it's going to keep me driving for a good while on the old parts.

I'm trying out the Penrite no leak steering box lube. This stuff is slow to pour. Like crack a beer and come back tomorrow slow. It took several fills with a 1.5 oz threaded funnel I made up to fill the steering reservoir.

I put off this repair as I thought it would be a can of worms. Once I studied all the books I had and one DVD video (Diablo A's Rebuilding 2 Tooth Steering, highly recommended) the mystery of the steering gear was tackled and I felt like I knew how to both tear it down and adjust it once back together.

Oh, one more thing. If you know you're not replacing the worm, you can do all this without removing the entire steering gear from the car. I covered the pedals in a towel, put a mat over the seat brackets, and laid the wheel either on the seat or on the mat, depending on what I was doing. All I removed was the floorboards, and the starter. Then once it was off the frame, I slung the engine end of the gear with rope from the radiator to firewall rods. Even easier.

The car had 71,000 miles on the meter when I did the frame off restoration. What's the experts guess that that kind of small wear on the sector shaft being the original part?
 
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