Steering box sector shaft

G

Gino

Senior Member
Hi, there is too much play in the steering. I have the box disassembled and on the perfectly tidy work bench. I see some wear on the sector shaft, is a little wear acceptable?
I believe the worm gear to be to be modern with 13 rollers.
Any advice on this appreciated.
 
Gino said:
Hi, there is too much play in the steering. I have the box disassembled and on the perfectly tidy work bench. I see some wear on the sector shaft, is a little wear acceptable?
I believe the worm gear to be to be modern with 13 rollers.
Any advice on this appreciated.
Click to expand...

Is the steering box concerned 7 tooth or 2 tooth? genarlly speaking, not acceptable. The fit between the bushes and the shaft should be about as tight as for the gudgeon pin (wrist pin). A little play goes a long way!
For the shaft to be worn, I think the box has done a lot of work so the endplay in the sector shaft ad the worm shaft might very well be excessive. Again, a little play goes a long way.
 
We are two toothed, the box and I. It has an excuse at 96 I’m only 70.
I’ll try to post some pics. I wonder, say this is reassembled on the bench, would I be able test the amount of play? Thanks
 
The two tooth box is easily adjusted on the bench. Adjusting it in the car is much more difficult. New box internal parts are finally available.

JLC
 
The usual problem for both 7 and 2 tooth is wear of the sector shaft. You can "see" the wear and in place you'll see "slop" front to back which translates to free play at the wheel.

The solution is new shaft/bushing/ream job.

Some have turned down the shaft a skosh (technical term) and used over thick bushing.

Some have turned down the shaft and used "boxed needle bearings" (Torrington is usual)

You can buy a new housing with needles installed that will fit the new shaft - this might be the most direct way. You can go the same way with a bushed housing.

Or - you can follow the instructions in the Service Manual for adjusting - and hope for the best. You want it TIGHT, almost galling at "mid span" and increasing but equal amounts of "free play" as the wheel is turned further from center.

The geometry of the Model A front end is such that turning from center causes the rolling wheels to "bear" the two tooth against the worm - either side depending. So free play during adjustment is desired - but only increasing as your wheel is turned from center. Follow the Service Instructions.

There are several good videos on Youtube on adjusting. Best done with the steering column OUT of the car.

Joe K
 
Joe K said:
...


Or - you can follow the instructions in the Service Manual for adjusting - and hope for the best. You want it TIGHT, almost galling at "mid span" and increasing but equal amounts of "free play" as the wheel is turned further from center.
...

Joe K
Click to expand...
I find that the difference between "too loose" and "too tight" when setting "just right" at the center of travel is very tricky to achieve. And if you are using the eccentric to set it, it will get knocked off when you tighten the jam nut. You may need to sneak up on it several times until you get it right. If I can't get it right on I generally set it on the tight side so that it can loosen in use.
 
If the tooth wear is just minimal surface wear but still even, there is a possibility that the two parts can still be adjusted for a zero clearance fit in the straight ahead centered position. If there is any divots in the worm gear then it is toast. Setting to zero clearance will make for a notchy feel to the steering movement and it will always have some play. The sector rotating shaft part must have no play in the bushing/shaft journal surfaces or it will always have play there.The two tapered rollers on the worm must have some pre-load so there is no play there either. Make it as tight as you can and it will have minimal play in the straight ahead centered location where it rides most of the time. It's normal to have play in the gears when off center. The farther it turns the more play it is allowed to have. This allows geometry compensation in turns so that is will turn properly.
 
As Rotor Wrench wrote about, the box is designed to have no play when straight ahead and some play when turning. The straight ahead position is adjustable by the eccentric screw. If it is loose in the center and tight at either end then the worm is too worn.

Somewhere there are instructions on how to adjust the box. Maybe the Red Book. I am not at home so I cannot check. If you cannot find instructions, it is not too hard to figure out.
 
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nkaminar said:
Somewhere there are instructions on how to adjust the box. Maybe the Red Book. I am not at home so I cannot check. If you cannot find instructions, it is not too hard to figure out.
Click to expand...

The Service Bulletins I mentioned. These come in two "media." Originals and the highest quality reprint (Ben Staub Pubs.) are done in the original size which is 8-1/2 x 11ish. Cream colored front page. Softcover. Tend to be a little pricey when found ($70ish) but generally preferred within the hobby.

You'll probably tie up the better part of $300 for original Service Bulletins in the original tied covers.

The Service Bulletins reprint that seems most found is the "yellow book." Dan R. Post Publications. Which is smaller perhaps 7 x 9, has "challenged" pictures, but is done up in true "bound book" style hardcover. Most of the Model A parts houses that sell the Service Bulletins sell this one but Ebay or Abebooks.com can bring this to you at around $10 - $20.

Either of these will tell you what you need to know.

The Les Andrews "Red Book" Model A Ford Mechanics Handbook has instructions, although this has not been my go-to in these matters.

The Model A Ford by Victor Page has a quick synopsis. At the time of the original printing Ford had just introduced the Two Tooth steering box. This book has been reproduced by MANY book houses and in many formats. I've seen this one as cheap as $7 on Ebay.

Joe K
 
Setting the steering too tight in the straight ahead position can make the car difficult to control at speed, just like over tight king pin bushes.Tight, but not too tight!
 
FWIW, I find the Les Andrews procedure in the Red Book to be quite adequate for setting up the two-tooth box on the bench.
 
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