Axle Key Installation

[MABidwell]

46 Super Deluxe

Trying to install rear hubs and I’m having trouble getting it to slide far enough over the axle to get the seal, washer and nut on to tighten it down. I’m assuming the problem is the key sitting too high - at least toward the inside where the taper is - meaning that I set the key back so far that the taper in the key isn’t lining up with the taper in the axle, so it’s riding high.

I’m attaching a couple of pictures and would like some advice on how to determine where the key should be located.

Alternatively, would it be a bad idea to file off the top of the key to get the hub to slide on?

Thanks,
Mark B

[rockfla]

The key looks like its fine, "sometimes" the drums can be really finicky and stubborn "Lining" up just right to fit over the bearing and the shoes (Make sure you adjust those in a little bit before you try to reinstall the drum) IF you haven't done that already.


A few of your threads LOOK like they have a little flat spotting on them, IF you have a die nut you "may" want to run that over them JUST to make sure they are good and crisp!!! AND CLEAN!!!

[ford38v8]

From yout pictures, it appears that the key is extending outward, thereby raising that end above the flat bed of the keyway. Apparently, all keys are not equal.


On another issue, I suggest that you remove the key, and with the use of grinding compound, install the drum and nut loosely, turning the drum by hand to seat the taper to the drum. This step has been made considerably more important now since you apparently have used emery paper, which provides no control of the depth of cut. Failing to perform this crucial operation will put your key and keyway in control of the drum remaining in position, rather than the taper to drum contact, which by design is intended to solidly seat the drum against turning on the axle.

[Ken/Alabama]

Chamfer the top edge of the key,it will help getting the hub on.

[69a]

You need to remove the key. Fit the drum to the axle with some oil or fine grinding paste. push it as far on as you can get it and accurately measure how far the axle protrudes. now fit the key and using a file keep removing metal from the top of the key where it touches (bearing blue or similar) until the drum goes on to the pre fitted position. The key does not need to touch the top of the slot.

[rockfla]

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How much play is in your axle in the above pictures???



Looking at your second picture you posted......IS it me OR is you axle not centered?? Maybe it's me BUT from your 2nd picture there "appears" to be more room at the top of the axle than at the bottom. MY 39 Mercury has a cork tapered axle seal that fit around the axle and "helped" keep the axle centered(AND rear bearing grease in). Hence my first post, EVEN with that axle seal the axle "sometimes" is still not 100% centered and getting the drum in the right spot over the bearing, shoes and axle centered (per se') takes a little maneuvering to get all 3 to line up and play friendly!!!!


38fordV8...I'm not following you on your keyway theory, could you explain it again or maybe differently....judging by the taper of the axle the keyway "looks" to be in and flat all the way across. NOT to be arbitrary or argumentative.

[ford38v8]

rockfla, the axle will never be centered until the drum is installed with its bearing.


Position of the key in the pictures may be an optical illusion. Keys must be aligned and fully seated within keyways.

[rockfla]

Originally Posted by ford38v8

rockfla, the axle will never be centered until the drum is installed with its bearing.


Position of the key in the pictures may be an optical illusion. Keys must be aligned and fully seated within keyways.

RIGHT
AND UNTIL he centers the axle the drum will not fit and "possibly" give the appearance of it being a "key way" Issue. THEN add the ability to get the drum over the brake shoes....ESPECIALLY IF they weren't adjusted inward when the drum was pulled, FURTHER limits the location (and the ability to move the axle and drum) relative to the bearing!!!
I Fought this exact issue on the right rear of my Mercury for at least 10 mins before IT slipped on just as it should.



AGAIN (I have a lap top so its easy to turn it sideways) BUT Look at the gap on the top relative to the bottom and where the axle is positioned.....IF he is trying to slide the drum on as its pictured and doesn't know that the axle HAS to be centered, key way OR Not....The drum isn't going to fit!!!! 2nd picture

[Newc]

Also one of our local V8ers had the top inside edge of the key 'grab' the hub. reason for an inside top taper? Newc

[Tinker]

yes it's model a reference, but trust me it didn't change. Do a google search. "fordbarn installing axle keys" lot comes up.


I guess it also depends on the key you have. Not all aftermarket keys are created equal.


https://www.fordbarn.com/forum/showthread.php?t=136160

[Mart]

Rock, the axle floats to a certain degree because the bearing is in the hub. There is a seal inside which the axle rests on, so if tapping the key in place it is important to hold the shaft up so you are not hammering on the seal.
It is sometimes helpful to look down the hub hole to see the keyway lining up as you slide the hub on.
There should be a taper on the key. This needs to be positioned correctly so the key will sit down snugly into the keyway.
Hubs should be lapped to the shaft. Hub bore and shaft must be spotlessly clean before assembly.
Hub should fit to same position with or without key.
Nut must be maintained eyewateringly tight.
Mart.

[deuce_roadster]

Have you tried a different key? It looks to me like the end of the key closest to the threads sticks up higher above the taper then the end nearest the bearing. Is this a new repro key? If so, it could be junk.

[V8COOPMAN]

.

Don't forget the fact that the keyway slot itself tapers-up to meet the axle surface at the inner end, as shown here. Hence, the need for the key itself to have a taper facing downward to accommodate fitting the ramp at the inner end of the keyway. Also note the fatal crack in this axle, more than likely caused by NOT tightening that big nut tight enough. DD

[MABidwell]

Thanks to everyone who offered advice.

I stopped working on it yesterday thinking that I might have to replace a damaged axle - so dismantle everything I've spent the past few months working on!

This morning, I re-read the comments along with a few more that had been posted and went back at it. Little by little, taking some material off the key, I was finally able to get the hub to fit on far enough that it seemed like it was good. The other hub didn't cause me any trouble at all, so the comment that "not all keys are alike" rings true.

Thanks again!

Mark B.

[Phil Gillespie]

Originally Posted by MABidwell

Thanks to everyone who offered advice.

I stopped working on it yesterday thinking that I might have to replace a damaged axle - so dismantle everything I've spent the past few months working on!

This morning, I re-read the comments along with a few more that had been posted and went back at it. Little by little, taking some material off the key, I was finally able to get the hub to fit on far enough that it seemed like it was good. The other hub didn't cause me any trouble at all, so the comment that "not all keys are alike" rings true.

Thanks again!

Mark B.

Dont forget to pull this up real tight with nut. 200Ft/lbs!!
Phil NZ

[deuce_roadster]

Good picture Dick in post 13, that is where they almost always break from being run loose.

[Tinker]

or running the taper up and outward. or just up. The tapered end is not so you can get the hub on easier in my opinion. It is used to increase bond as the axle is tightened to 200lbs.


If the axle key is installed with the little end out and/or taper up of the axle it is on wrong in my opinion.

[ford38v8]

Originally Posted by Tinker

or running the taper up and outward. or just up. The tapered end is not so you can get the hub on easier in my opinion. It is used to increase bond as the axle is tightened to 200lbs.


If the axle key is installed with the little end out and/or taper up of the axle it is on wrong in my opinion.

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.

[V8COOPMAN]

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.

Damn, Dude.....You've got a way with words every now and then....Nicely-Put!
And, most of the time at this place, we don't need no stinkin' OPINIONS. With MOST of the matters that we usually discuss here, many of the opinionated answers that some want to throw out there straight from the butt usually confuse matters, or at worst, give a new member or inexperienced old Ford owner a totally incorrect idea for what he's asking. You GO, Alan! DD
.

[deuce_roadster]

Most user tightened axle nuts I have removed have been WAY too loose and the hubs usually don't need my KRW puller. Like the picture Dick posted I have removed many cracked axles that were still in service. If you look at the ends of broken ones you can see that they were cracked for a very long time. It is a good thing the axles were made of good steel and were many times stronger then the minimum needed. Educating new owners of the idea that the hub is driven by the taper and not the key is something I feel I should always do. I also suggest using crack detection methods when the hubs are off of a vehicle you don't already KNOW the condition of the axles.

[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!

[Mart]

Thanks for explaining the 5 gear method, Pete. I had never heard of that one.

Mart.

[Pete]

Originally Posted by 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!

Look up a neat movie called "Red Dirt Rising". It is about all of that keen old stuff.

[V8COOPMAN]

Originally Posted by Pete

Look up a neat movie called "Red Dirt Rising". It is about all of that keen old stuff.

This SHOULD be the full movie.....Click on the link BELOW! DD


https://www.youtube.com/watch?v=-arEWlUVkJo

[Phred]

The five gear locker sounds intriguing and relatively simple. I am have trouble understanding/picturing the method. Would someone be able to post photos or a drawing to help me understand?

Would the same "4" gear locker method work in a Model A banjo?

Thanks in advance
Peace, Phred