Axle Key Installation

[Tinker]

Originally Posted by ford38v8

Tinker, I’m glad you used the term opinion, because in my opinion, your opinion as stated in the first sentence is wrong, and here’s why: the taper needs no help to increase bond, and in fact, any force exerted by the key would decrease bond between hub and taper shaft, as any interference between shaft and hub that operates to exert an unequal force around the circumference presents an opportunity to break the bond between the two surfaces. I’m no mathematician, and I haven’t put a micrometer on a key, but I’ll lay odds that keys were not intended to be an interference fit between axle and hub, and that someone here will come up with the Ford specs to confirm the point. If you just think about it, if your theory were correct, the tolerances required of all related components would boggle the mind. My opinion then, total depth of matching keyways must exceed the height of the key.

It's technically the 3rd sentence. But you agree how the axle key is installed. Whether is adds any bond or not. The taper is there for some reason and it's not to put the hubs on easier. Probably not for axle force as I mentioned, the width of the key and it's fit relationship to the axle groove would be more important.


I don't mind discussing things and I like your thoughts and see your knowledge.

whether it comes from my butt or others on here. (not you)

[koates]

The taper is the part that takes all the load or driving torque from the axle to the hub and that is why it has to be a very clean,dry, tight fit. The key is almost an afterthought or is it a backup for the taper or to locate the hub, but the hub does not need to be located does it. I would guess that the key does not really have to be there at all. I had a friend who would oil up the taper so that the hub or drum was easy to remove to work on the brakes. I could not convince him that the taper had to be very clean and dry. About 200 ft lbs is required on the axle nut. This guy was only doing the nut up to 50 ft lbs. I guess in that case the key was doing all the work. Also the keyway in the axle weakens the axle and is prone to cracking in that area. Have to be very very particular when fitting the drum on those axle tapers. Regards, Kevin.

[V8COOPMAN]

Originally Posted by koates

The taper is the part that takes all the load or driving torque from the axle to the hub and that is why it has to be a very clean,dry, tight fit. The key is almost an afterthought or is it a backup for the taper or to locate the hub, but the hub does not need to be located does it. I would guess that the key does not really have to be there at all. I had a friend who would oil up the taper so that the hub or drum was easy to remove to work on the brakes. I could not convince him that the taper had to be very clean and dry. About 200 ft lbs is required on the axle nut. This guy was only doing the nut up to 50 ft lbs. I guess in that case the key was doing all the work. Also the keyway in the axle weakens the axle and is prone to cracking in that area. Have to be very very particular when fitting the drum on those axle tapers. Regards, Kevin.

Kevin (Koates) KNOWS HIS Shit, and EVERY word he wrote above is gospel! The two tapers tightly-fitted together, clean & DRY as a bone is exactly how that marriage is designed to work. It works on the same principle as a "Morse Taper". Like Kevin stated, the key stock is almost without any necessity. DD
.

[ford38v8]

So, I think we all agree now that the key is redundant. It is a fail safe, intended to provide a measure of assurance that the axle will not spin on the hub, should an installation be performed somewhere sometime in a manner contrary to methods specified by Ford. Yes, we have plenty of examples of what invariably happens with incorrect installation. That the key/keyway does itself compromise the integrity of the system is demonstrated in so many, many failures, I just wonder how the numbers of catastrophic failures would compare if Ford had not incorporated the key into the design.

[Tinker]

As Bruce Lancaster used to say, if you have the right answer nobody says anything, but if you don't people will move the earth proving you wrong.


Great stuff! thank you for the time. I think I'm really learning something. I'm not being sarcastic.


Even at full engine torque or when you add more torque to the engine. You think it will not ever spin without the key?

[V8COOPMAN]

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Originally Posted by Tinker

I think I'm really learning something. I'm not being sarcastic.


Even at full engine torque or when you add more torque to the engine. You think it will not ever spin without the key?

You say that you think you're learning something. So, howz-a-bout what you're forgetting? You're forgetting ALL of that smoke that those skinny-assed 6.00 X 16 tires had built-in to them from the factory in those days. Henry's 'boys' with the slide rules designed those axles and hubs so that any EXTRA torque would simply be converted to all that smoke that was always stored in those skinny baloneys, long before any slippage occurred at those tapers between axle and hub. DD

[Tinker]

What if I put wider radials on? a common thing here. I run biaplys cookie cutters, but I'm increasing in the the little bus. Just a question.

[ford38v8]

Originally Posted by Tinker

As Bruce Lancaster used to say, if you have the right answer nobody says anything, but if you don't people will move the earth proving you wrong.


Great stuff! thank you for the time. I think I'm really learning something. I'm not being sarcastic.


Even at full engine torque or when you add more torque to the engine. You think it will not ever spin without the key?

Hoo, boy, that’s a question beyond my understanding of the principle. NOT EVER is a pretty confining condition! What I am comfortable in saying is that as long as the installation was performed correctly with components in good condition, I’d bet my life on it.

[Tinker]

Thanks for the clarification earlier.

[V8COOPMAN]

Originally Posted by Tinker

What if I put wider radials on? a common thing here. I run biaplys cookie cutters, but I'm increasing in the the little bus. Just a question.

Just an answer here, but I don't believe the size of the tire comes into play when attempting to determine the torque transfer abilities (in ft. lbs.) between Ford tapered axle and matching tapered hub. The only time the size of the tire will make a difference is when one approaches the slip (smoke-release) torque value of the skinny tire. Then, the size of the bigger tire matters ONLY in that it shows that you have no self-control over knowing when enough is enough, and that you should probably drive your Honda to the local Saturday night "Tastee-Freeze" car show, rather than the "little bus". DD

[Tinker]

Geez you don't know me. I drive my original 36 coupe ( I do have 39 brakes) to the tasty freeze with a flathead and 3sp. No t5. Also a mostly orginal 38 truck with a mitchell splitter so I can do 70 on the highway. I don't understand your anger and thinking I have a honda or should for some reason? Maybe that's a personal slam to me or you hold all the flathead info. Honda is a good vehicle. You might consider not making general accusations to make a point. Even though the acronym is FB it still is the fordbarn not facebook.

I don't know what the slip/smoke matrix is either. I asked a question. Well I guess dragsters with banjos should put pie cutters on.


Just a question...

.

[V8COOPMAN]

Originally Posted by Tinker

Geez you don't know me. I drive my original 36 coupe ( I do have 39 brakes) to the tasty freeze with a flathead and 3sp. No t5. Also a mostly orginal 38 truck with a mitchell splitter so I can do 70 on the highway. I don't understand your anger and thinking I have a honda for some reason? Maybe that's a personal slam to me. Honda is a good vehicle.

I don't know what the slip/smoke matrix is either. But I won't get weird protecting it. I asked a question and you are aggravated I did so. Well I guess dragsters with banjos should put pie cutters on.


Just a question...

.

Geez Tink, YOU don't know ME! What gives you the idea that I have anger for you. When I'm angry, I usually stand up and scream "I'm MAD, Charlie Brown"!

If you think a Honda is such a good vehicle, why would my assuming that your 'daily' is a Honda imply a personal slam toward you? My deceased dad's neighbor across the street has a Honda, and I don't feel any anger toward him! Then again, I haven't seen him since Dad's funeral.

Why would you think I'm aggravated? We only discussed the mostly misunderstood taper and key of these drums & axles, cleared-up some misconceptions, and even had a few laughs with it. Man, now you have me wanting to go take a squig out'a the vodka bottle. Sorry I rattled your cage so badly! No more smoky burnouts with you, friend. We'll just go the KISS system. Just make sure that big nut has a little more than TWO-BIG on it! DD
.

[Tinker]

That's a lot going on there. At noon tomorrow central time I will go out and do a burn out in your honor. If you like and depending on your time you can do the same.. or not. We are the same people arguing about nothing but little details. Be well. I don't live in a cage, so nothing to rattle.

Originally Posted by V8COOPMAN

ONLY in that it shows that you have no self-control over knowing when enough is enough, and that you should probably drive your Honda to the local Saturday night "Tastee-Freeze" car show, rather than the "little bus". DD

[ford38v8]

Hey you two! Grab a beer and chill! I detect a slight grin outta both of you anyway, so gimme five and take a seat.

[Mart]

All I can add is any time I tried to do a burnout in an early Ford I broke something.

Mart.

[V8COOPMAN]

Originally Posted by Mart

All I can add is any time I tried to do a burnout in an early Ford I broke something.

Mart.

Ah yeah ....I think that has something to do with that part about knowing when enough is enough! DD

[Pete]

For what it is worth and contrary to popular now days beliefs, early Ford rear ends CAN be made to stand up to large abuse. Many of the top sprint cars, midgets and modifieds in the old days ran early V8 and model A rear ends and to add to the abuse, they were locked, usually with the 5 gear method. While weld on safety hubs were required, they were seldom needed.
The reason they were so reliable was the 100% lap fit of axle to hub that everyone used. Hard high nuts were used also so the axle thread had full length engagement.
The pavement sprint cars and modifieds ran 9 or 10 inch slicks in those days also which added to the axle abuse.

[ford38v8]

Pete, good to hear from the perspective of a racer. Perhaps you could explain a term you used for non-racers? I’ve seen welded spiders, but have no idea what you mean about the 5 gear method of locking rears?

[Pete]

Originally Posted by ford38v8

Pete, good to hear from the perspective of a racer. Perhaps you could explain a term you used for non-racers? I’ve seen welded spiders, but have no idea what you mean about the 5 gear method of locking rears?

The 5 gear method of locking rear ends first got started with stock car racing. This was when guys were racing junkers fresh out of the wrecking yards. Many had no welders or even a torch so welding or brazing was hard to come by. The only tool needed was a bench grinder.
Anyway, you take the spider gear cross and cut or grind 3 of the 4 shafts off.
Then scrounge up one extra spider gear. There is a raised polished area on the back of each gear. You must grind this raised area off till it is flush with the teeth. Do this to all 5 gears. Put one gear on the single cross shaft remaining and assemble that and the other gears in the carrier. If they won't go all the way down, grind more off the backs till the 2 halves of the carrier will go together and bolt up tight. Take the carrier apart and assemble all of the parts as you would a normal rear end.
These always seemed to last longer than welded ones or even a spool. Probably because there was a few thousandths slop between the axles due to cumulative tolerances between the gears.

[ford38v8]

Thanks Pete, looks like I’d need hands on to really understand your 5gear, but I get the gist of it! Sounds strange that a circle tracker could get a junker on the track without a red wrench, but there must still be a few more things to learn in my old age!