My p15 steers like a shopping cart.

[Loren]

20 hours ago, D35 Torpedo said:

I don't understand how a worn worm would cause binding, only play. The wear on the worm and roller is minuscule compared to that of the roller and pin. These are slow moving parts. Even without oil, they can go without wear for a very long time. The roller and pin get hammered out from road impacts like potholes. Once the roller has slop, the sector can freely move. In the center, both gears are square to each others. The roller is loaded evenly against the pin. At this point only end play can be exploited. But at either end the roller isn't loaded evenly. It has less tooth engagement and forces are vectored. Now end play has a greater effect and pin slop is now a factor. Hence, greater play off of center. There is zero adjustment to be made on the worm. Just shim the bearings to zero lash. All the adjustment is in the sector screw. The same forces that hammer the roller and pin take out the bearings over time. Anyway, that's my full analysis based on my findings and experience. 

Okay lets try to state this another way.

A worm gear is essentially a thread. In a steering gear that thread is curved to the radius of the sector’s movement. The roller on the sector is not really a nut or even a half nut. It basically contacts the worm with one of its three teeth on a very limited area when everything is perfect. Start getting wear or damage and the other two teeth start getting involved. Only its more complicated than that because of helix angle of the sector. One of the out board teeth will be over center and the other will be under center. Add to that those outboard teeth are in contact with the adjacent teeth on the worm and because the center tooth is worn ( or in contact with a worn worm tooth ) it is putting them out of position.

Someone wanting to adjust out the wear will screw down the sector adjustment and that makes the whole thing worse.

Bottomline: The way to fix it is a new set of worm, sector roller, bushings and bearings.

[jgreg53]

I've looked for replacement gears. Not easy to find.

[Loren]

The last kit I bought for my 29 Model A I got from Macs to rebuild a 1953-56 F 100 pickup box. The price was $299.99 and it came with everything I needed.

To adapt the pickup box to a Model involves lots of engineering and machine work…way too much to describe here.

But I learned a few things, the steering gears were made by Gemmer for Ford for U.S. models and Ingersoll for Canadian models.

I would be curious if one of our members has one loose that they can see if it has a name cast on the side.

If Gemmer made them its likely the parts could be made to fit.

The parts I have seen sure look like the F 100 parts which are readily available.

 

Sounds like a worthy project for investigation.

[jgreg53]

I see quite a few steering tubes with a worm gear for various Willis jeeps . I wonder if anyone knows of a crossover number . 

Edited March 20, 2023 by jgreg53

[D35 Torpedo]

On 3/18/2023 at 8:14 PM, Loren said:

Okay lets try to state this another way.

A worm gear is essentially a thread. In a steering gear that thread is curved to the radius of the sector’s movement. The roller on the sector is not really a nut or even a half nut. It basically contacts the worm with one of its three teeth on a very limited area when everything is perfect. Start getting wear or damage and the other two teeth start getting involved. Only its more complicated than that because of helix angle of the sector. One of the out board teeth will be over center and the other will be under center. Add to that those outboard teeth are in contact with the adjacent teeth on the worm and because the center tooth is worn ( or in contact with a worn worm tooth ) it is putting them out of position.

Someone wanting to adjust out the wear will screw down the sector adjustment and that makes the whole thing worse.

Bottomline: The way to fix it is a new set of worm, sector roller, bushings and bearings.

The spool gear has two teeth. I put a full kit in my box. So I explained exactly what I saw. What I saw doesn't match your logic. No offence, but feel like if you read my posts, you wouldn't be explaining it to me like I'm a kid. It loosens up as it moves from center. All the wear is on the spool gear and pin. Like a said, generally speaking, you're correct. However, in this case things are different. You might say my case is a special one. But my box is the same as all the rest. Therefore suffering from the same design flaws. It's just a matter of how far gone it is. Not trying to argue. Just seems like my points are not getting across.✌️

[Loren]

8 hours ago, D35 Torpedo said:

The spool gear has two teeth. I put a full kit in my box. So I explained exactly what I saw. What I saw doesn't match your logic. No offence, but feel like if you read my posts, you wouldn't be explaining it to me like I'm a kid. It loosens up as it moves from center. All the wear is on the spool gear and pin. Like a said, generally speaking, you're correct. However, in this case things are different. You might say my case is a special one. But my box is the same as all the rest. Therefore suffering from the same design flaws. It's just a matter of how far gone it is. Not trying to argue. Just seems like my points are not getting across.✌️

No offense taken. I am a week or two from having mine apart and then I can be on more solid ground. My experience has been solely on the Gemmer box. Professionally the cars I worked on were all rack and pinion setups and that is a different kettle of fish altogether. The one in my car is in very good shape, it just leaks. Perhaps I am missing something and will be able to see it right away. Its always easier when you can put your hand on it.

[D35 Torpedo]

9 hours ago, Loren said:

No offense taken. I am a week or two from having mine apart and then I can be on more solid ground. My experience has been solely on the Gemmer box. Professionally the cars I worked on were all rack and pinion setups and that is a different kettle of fish altogether. The one in my car is in very good shape, it just leaks. Perhaps I am missing something and will be able to see it right away. Its always easier when you can put your hand on it.

 

That is true. Mine was in rough shape. The bearing races had roller imprints, the screw has some pitting and the sector gear has a bunch of play on the pin. It certainly helps to start with a good unit.