7 Tooth Box..Question

J

jg61hawk

Senior Member
I have a 1929 Roadster with the 7 tooth steering box. I have a question: I did the SEARCH on this forum and it appears the only two available adjustments, on the 7 tooth box, will have ZERO effect on any steering wheel lash ( free play). Is that correct?

Interesting observation I made while laying under the car while the wife rocked the steering wheel... I saw lubricant coming out the seal between the steering box and the three screwed side plate. Turns out the cap bolts were all pretty loose. Hopefully that explains some of the oil leaking out of the box.

Would I be a real jerk if I did simply turn the adjuster screw about a 1/4 turn without removing the drag link etc..? I was thinking of jacking the wheels off the ground and seeing if the adjuster did anything...but from what I read it is for output shaft (sector shaft) play in and out.... Comments welcome please...thanks...
 
Although I don't have the 7 tooth steering box, I do my adjustments to my box with the wheels off the ground. Point the wheels straight ahead when you do the adjustments. Tighten any loose bolts first. After adjusting the box, test for binding by turning the wheel lock to lock.
 
There are indeed only 2 adjustments on a 7 tooth steering box. The end play in the steering shaft is adjusted at the time of assembly by the addition or removal of shims. The end play in the sector shaft can be done with the box in t he car but unless you take the pitman arm off, you can't get a good feel on it.
Many are critical of the 7 tooth steering box but I regard them as quite a good thing. Once rebuilt properly, they will last many years. Of my 4 Model As, the one I like driving the best just happens to have a 7 tooth steering box in it.
 
I did post this a while back . The 7 tooth worm is "double start" so you can get some play out like this . Remove the pitman arm first . Put a tray under the steering box . Remove the 3 bolt side cover the oil will drip into the tray if grease it might not . Push the sector shaft in so it is disengaged from the worm .Rotate the steering wheel exactly half a turn and push the sector shaft back in and reassemble . The sector will now be riding on what was the less worn back side of the worm . If this does not cut down some freeplay then someone has done this before .

John in sunny cool West Drayton London
 
Tighten the bolt on the pitman arm where it joins the output shaft on the steering box. You'd be surprised!
 
I like that trick. John Charlton. I've gone through my 7 tooth steering box twice and I've replaced everything, bearings, worm and sector shaft, shimmed the end play and the best I've got the free play is about 2"s. Tightened the steering arm down with a Johnston bar. That took up about 1/2". So I'll try this trick and see if it helps.
 
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The trick works best with a worn worm where the trick has not been done before . You wont notice much difference if your worm was new when you replaced it . Let us know what transpired .

John in cloudy cool evening West Drayton London .
 
Hi John. Thanks for the hint to remove the back lash in a 7 tooth box (10-25-21). I did this yesterday, and took the car for a run about an hour ago. Very little if any slack in the steering. When I re did the pitman arm, tried to tighten the bolt, but a little too much and it broke. Replaced with a new grade 8 bolt to 40lbs. It also helps if the right tyre pressure is applied, as I at one time only had 30psi...35psi seems to be a lot better! Many thanks for the hint. Hopefuly a picture of the car will show. Had to have a shop rebore to 40+ but the rest is all my own work.
 

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I've only rebuilt one 7-tooth box. To get it right I replaced the sector & worm gears with new ones. To get the best mesh of the gears I had to use black magic marker I did not have machinist blue. Let's see if I remember this right: I coated the sides of the sector gear teeth with the marker. Assembled the complete steering box, replacing what was needed besides the sector/worm gears. Adjusted the box as best I could. Rotated the steering wheel completely both ways a few times. Dissembled the steering box. Checked to see how much and where the marker paint had rubbed off the sides of the sector teeth. Which would indicate high spots on the sector teeth. And prevent the teeth on both gears from meshing fully. I then carefully ground down the indicated high spots with my Dremel tool. Remarked the sector teeth as before and then reassembled the steering box and repeated the sequence described above. It has been about 12 years since I have done this so I hope I'm describing the procedure correctly. After doing this about 7, 8 or more times. The steering wheel had maybe a 3/4" play. I was justifiably proud of this accomplishment as I am more of a "parts-changer" then a true mechanic. I hope I have described this procedure correctly and if anybody knows better please chime in.:eek: This work was done with the steering gear clamped in a large vise. After assembling the gear back into the car I had to readjust the sector end play for the best fit. Even with 2-tooth steering boxes I've had to always readjust the mesh of the gears once I installed them into the cars.;)



Bob-A:D
 
john charlton said:
I did post this a while back . The 7 tooth worm is "double start" so you can get some play out like this . Remove the pitman arm first . Put a tray under the steering box . Remove the 3 bolt side cover the oil will drip into the tray if grease it might not . Push the sector shaft in so it is disengaged from the worm .Rotate the steering wheel exactly half a turn and push the sector shaft back in and reassemble . The sector will now be riding on what was the less worn back side of the worm . If this does not cut down some freeplay then someone has done this before .

John in sunny cool West Drayton London
Click to expand...

thanks John, i never heard of that before.
i am going to take a look at that idea today, i have easy access to the steering box as the engine is out of the car.
lets give it a try.
 
1946 said:
Hi John. Thanks for the hint to remove the back lash in a 7 tooth box (10-25-21). I did this yesterday, and took the car for a run about an hour ago. Very little if any slack in the steering. When I re did the pitman arm, tried to tighten the bolt, but a little too much and it broke. Replaced with a new grade 8 bolt to 40lbs. It also helps if the right tyre pressure is applied, as I at one time only had 30psi...35psi seems to be a lot better! Many thanks for the hint. Hopefuly a picture of the car will show. Had to have a shop rebore to 40+ but the rest is all my own work.
Click to expand...

Nice!
 
john charlton said:
I did post this a while back . The 7 tooth worm is "double start" so you can get some play out like this . Remove the pitman arm first . Put a tray under the steering box . Remove the 3 bolt side cover the oil will drip into the tray if grease it might not . Push the sector shaft in so it is disengaged from the worm .Rotate the steering wheel exactly half a turn and push the sector shaft back in and reassemble . The sector will now be riding on what was the less worn back side of the worm . If this does not cut down some freeplay then someone has done this before .

John in sunny cool West Drayton London
Click to expand...

well John mine is just too far gone, it didn't help on this one but it is a good idea that i will have to remember.
thanks
 
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