axle key

marty in Ohio

marty in Ohio

Well-known member
Model A friend, Bob, pulled off the rear hubs from his '29 tudor today and found that the axle keys were stamped with the Ford script logo. Do you guys think these keys were original? We can't seem to get a picture to post, but were wondering if these are common. Both keys were in very good shape.
Marty
 
I don’t know about the Ford name on keys, but please don’t forget to re-torque the axel nuts to 100 foot pounds when you put it back together. Enjoy.
 
The FORD name would indicate they were made by Ford Motor Company. Whether original to the 1929 in question will be hard to prove as during the early 1930's, the height of the depression years, The Ford Motor Company had an advertising campaign urging owners to bring their Fords to a Ford dealer for repairs using genuine Ford parts. The parts sold by dealers at that time, to the replacement market, were marked with Ford name, the part number, or both.
 
marty in Ohio said:
Model A friend, Bob, pulled off the rear hubs from his '29 tudor today and found that the axle keys were stamped with the Ford script logo. Do you guys think these keys were original? We can't seem to get a picture to post, but were wondering if these are common. Both keys were in very good shape.
Marty
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If the axle nuts were kept tight throughout the car's existence, the original keys will last indefinitely as they are merely going along for the ride. The taper of the hub and axle shaft is what handles the load, not the keys. Consider machine tools, like a Bridgeport mill. They use what is called a Morse taper to drive a cutter, etc. without any key at all. The tight fit of the taper does it all.
 
Thanks for the responses guys. As soon as we receive the fiber washers we'll put it back together again. 100 foot pounds, got it!
Marty
 
I've found a couple script axle keys too. Also just came across a lower water inlet casting that is Ford script, also has a small triangle manufacturer's mark. Anybody know any history on it?
 
100 ft-lbs on a taper??? Way too much torque in my opinion. The taper centers the axle and the shear key reacts the driveline torque. What is important is that the shear key have a snug fit (no play).
 
Bob Bidonde said:
100 ft-lbs on a taper??? Way too much torque in my opinion. The taper centers the axle and the shear key reacts the driveline torque. What is important is that the shear key have a snug fit (no play).
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One of the great things about this forum is all the different views members have and sometime voice.

I guess you could refer to the rear axel key as a “shear key”, but I don’t believe that is correct. The torque on the rear axel taper along with the key guidance is what makes things work.

These are not like shear pins on snowthowers or outboard motors. They are guides.

Please check the factory spec’s. One of the quickest ways to break a key is to incorrectly torque rear axel nut. Enjoy.
 
Remove the shear key and the Model A will not go. The axle will spin in the drum because the friction of the tapered axle-drum hub cannot react the driveline torque.
 
Bob Bidonde said:
Remove the shear key and the Model A will not go. The axle will spin in the drum because the friction of the tapered axle-drum hub cannot react the driveline torque.
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Bob:

I agree. If key is removed/broken and torque on taper is to loose, car will not move. If torqued properly, car will still move even without key. However, the axel will eventually start spinning in hub and car will stop.

One of the reasons that axel keys break is to little torque on axel nuts which allows the hub to move on the axel straining the key.

I do not agree with you on this being a shear key/pin. You need the correct torque on the axel. That is one of the reasons a wheel puller is needed to remove the rear hubs. Wheel wobble is another reason for proper torque. The key also keeps the wheel from turning on axel when tightening the axel nut.

I have an orginal service manual. It states 100 foot pounds of torque, plus or minus. Some adjustment is needed to get the cotter pin in.

Loose rear axel nuts break keys, and cause ware on axels and hubs. Enjoy.
 
Bob Bidonde said:
100 ft-lbs on a taper??? Way too much torque in my opinion. The taper centers the axle and the shear key reacts the driveline torque. What is important is that the shear key have a snug fit (no play).
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The problem w/anything less than 100 ft-lbs is the sideways flexing strain on the taper when going around corners.
 
I believe it's the taper that transmits the torque not the key. The Model A generator has no key, also look at machine tools such as lathes and mills.


Bob
 

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yes the Ford script key is an original ford or service replacement. Per service bulletins Ford used the Ford script on many service parts so customers knew they were getting genuine Ford parts. They specifically call out "gyp" parts in the service bulletins


I don’t hesitate with good threads to torque to 125 ft lbs.
I’ve seen too many damaged axles and hubs from being loose and undertorqued. I’ve gone to 150 without any issues. I pull hubs and drums every week on cars and more often than not they are too loose. Compromised axle threads can be taken into account but should ultimately be replaced anyway.

Key ways must be tight and threads good and adequate torque applied.
Not trying to be against a few but if You guys who don’t want keys just remove them from your pinion gear and hubs and run them with the taper fit.
Larry shepard
 
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We had to fire a mechanic decades ago for a similar reason. Its not the only reason he got fired, he insisted on changing valve cover gaskets, carburetors, etc. with his air gun. He would pick the cars up on the lift by the bumpers. He would leave the rear hubs loose so they could be pulled off easily. He insisted that the key was all that was needed to carry the load. We got sick of making so many tow calls and our customers weren't very happy. So we made him go on the service call and fix the car right where it broke on his own time which still didn't teach him a lesson. After awhile it was still time to let him go.
 
Patrick L. said:
We had to fire a mechanic decades ago for a similar reason. Its not the only reason he got fired, he insisted on changing valve cover gaskets, carburetors, etc. with his air gun. He would pick the cars up on the lift by the bumpers. He would leave the rear hubs loose so they could be pulled off easily. He insisted that the key was all that was needed to carry the load. We got sick of making so many tow calls and our customers weren't very happy. So we made him go on the service call and fix the car right where it broke on his own time which still didn't teach him a lesson. After awhile it was still time to let him go.
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Ignorant and arrogant is a bad combination!
 
Synchro909 said:
Ignorant and arrogant is a bad combination!
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LOL. Yep.

Same guy. We got a service call and I went. Super cold morning and a Detroit 71 series wouldn't start. Big surprise huh. I pull up and this clown has the mouth flipped open and is grabbing and firing up the rose bud. The driver is standing next to him, I just kinda grab him by the arm and pull him back with me. This monkey starts waving that torch along the engine block to warm it up. Of course as was common in the day was a big *** can of ether mounted on the firewall. That tells me the engine is already ether bound. It didn't take long and the side of that engine came apart, blew the tire right off the rim and broke his arm in a couple places.
So, I then had to take him to the hospital and then tow the truck to the shop and change an engine.
 
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