MTFCA Forum

Hi All,
I've seen an example of a rear axle where the keyway was very damaged, and wondered if anyone had attempted to do any welding and grinding to get the keyway area back to normal. Is this a practical thing to do? I have some slight damage on the axle at the keyway and wondered if I could/should attempt to repair it so the key will stay in the slot better. Thanks,
John

Welding would be the last repair I would do. Right after replacement.
Soooo How bad, whats the issue?
Key a little loose : prick punch for a tight, stay in place fit.
Too loose for a punch : make a stepped key.
Chunk missing or crack : replace it.

Welding on one side is most likely to warp the axle end from the heat,
not to mention messing with the metallurgy to invite cracks.

Back in the late 1960's when my Dad and I were restoring my grandfather's 27 coupe, we encountered a badly worn keyway on an axle. Not having an alternative axle to use, the local machine shop took the axle and cut a new keyway, 180 degrees around the axle from the original. Its still holding up that way.

I've thought of doing d the same thing to my axles whose only problem is a buggered keyway. Good to hear about your and your dads experience.

RGould1910 wrote: ↑

Thu Aug 24, 2023 3:39 pm

I've thought of doing d the same thing to my axles whose only problem is a buggered keyway. Good to hear about your and your dads experience.

If you are going to the trouble of removing an axle to mill a new slot, Why not replace it?
Good quality repop axles are available today & relatively cheap, although, personally, I would prefer to replace with a good original axle.

This thread is about repair.

RGould1910 wrote: ↑

Thu Aug 24, 2023 6:29 pm

This thread is about repair.

Ok.
Throw out safety & correct function.
Its a farmers fix. Pound in some bailing wire.
Only needs to hold for the next mile. My mistake.
Then go with the easiest fix - JB weld. Good enough.

Is this a fix you would do on your 1910 touring??

I wouldn't do it! Breaking an axle while on tour could cause you to get stuck or worse cause you to roll over.
Norm

John, no self respecting farmer would use bailing wire for such a repair. Baling wire perhaps. It is nice and soft and very easy to work with.

Allan from down under.

I think you would be better to cut a new key way. however As long as it was in the taper I couldn’t see it affecting it too bad if you didn’t let it cool too fast. I have seen welded up cranks where the flywheel bolts on and I have had a machine shop weld up the end of an axle and cut new splines on it on a dodge truck and have no problems. However I welded a tack on a rear axle of a 58 chev to keep the bearing on and it only lasted a few months and split right where the small tack was. But personally I would try it if it was only in the tapered part.

I wonder what other stresses the axle has been subjected to in the last century? I not only replaced both of my axles but installed safety hubs to transfer some of the load to the axle tube. I've driven my car 9000 miles since with no issues.

FWIW - the buggered keyway is probably due to the axle nut being loose. I have seen dozens of axles ruined in this manner. Check you axle nuts - they need to be tight, really tight!

First of all John, the poster asked about whether a specific repair would work. I'm sure he knows he can replace the axle with a modern one. With regard to cutting a new keyway, I've often thought of doing that myself on a number of axles I've collected over the years. However I don't have the tooling to do the work but was pleased to see someone had successfully done that and it held up. For you to poo poo these attempts at repair when not asked suggests you as a few others on this forum see yourself as the expert, the go to guy that has all the answers to anything T related. My father had a saying for people like you
"If you bought him for what he's worth and sold for what he thinks he's worth, you make some real money!"

I would have to agree with speedytinc and Norman. I replaced both axles on my 24 touring because threads on the ends of both axles were stripped. Welding on the axle shaft would could cause the metal to crystalize and that would be a break ready to happen. I personally would not chance it. Good luck with this repair!

speedytinc wrote: ↑

Thu Aug 24, 2023 5:22 pm

RGould1910 wrote: ↑

Thu Aug 24, 2023 3:39 pm

I've thought of doing d the same thing to my axles whose only problem is a buggered keyway. Good to hear about your and your dads experience.

If you are going to the trouble of removing an axle to mill a new slot, Why not replace it?
Good quality repop axles are available today & relatively cheap, although, personally, I would prefer to replace with a good original axle.

John, Back between 1965 and 1970 when I was in high school and, then, college, and my dad and I were restoring his Dad's, and my Grandfather's 27 coupe, it was decades before the internet and although some of the major T suppliers were in their infancy of business, the only one close to us was Specialized Auto Parts in Houston. There were no salvage yards with Model T's in them as they were all scrapped out during WWII, and we didn't know more than a couple of T owners in our area. We didn't have a source for new or good used parts in our area, so we had to use what we had. All the original fenders were rusted off before they met the running boards, so we had to weld in metal and use body filler for the contours. My Granddad had cut the coupe decklid to make a pickup out of it, installing a wooden box, so we had to buy a reproduction roadster decklid (which was available); cut it and graft the bottom part of it to what was left of the top part of the original decklid. We had to use what we had or what was available. Like the old saying, Necessity Is The Mother of Invention.

OK,
Let's look at this like adults the OP asked about a possible repair? So lets assume that the key ways are both in the same condition. ( i'm thinking
if the axle keyway is worn so is the hubs?) So if we can make a key that fits both that is good. Welding on a axle is just not a good idea unless
you are a certified welder & a fantasic machinest. Look for a metric key & spend the time to make it fit, otherwise replace the hub & axle!!
Craig.

Craig Leach wrote: ↑

Fri Aug 25, 2023 1:24 am

OK,
Let's look at this like adults the OP asked about a possible repair? So lets assume that the key ways are both in the same condition. ( i'm thinking
if the axle keyway is worn so is the hubs?) So if we can make a key that fits both that is good. Welding on a axle is just not a good idea unless
you are a certified welder & a fantasic machinest. Look for a metric key & spend the time to make it fit, otherwise replace the hub & axle!!
Craig.

Craig, You are correct, the axle we had to have a new keyway cut in, also had a worn keyway in a wire wheel hub. Fortunately, I was able to locate and buy a good used one through an ad in Hemmings Motor News.

Thank you all for your replies. I won't try to do any welding on the axles. One side (don't remember which) was in pretty good condition, the other had some damage. The key sat in the slot, but was a little wobbly on the damaged side; so I got new keys. I put in the new keys which helped; but I just wanted a little insurance. So far, the car drives fine. Maybe making an oversized key to fit tighter is the way to go; otherwise a new axle would be in store.
Thanks again,
John

Paint it!

Old trick of my grandfather's was to paint the axle shaft when assembling. While the paint is wet slide on the hub and bolt everything together tight. It's good to hear the original question addressed so a wise decision could be made in this case not to weld. On another forum I inquired as to how a starter handled 12v. Instead all I received was a wealth of "keep it 6v" the conclusion I came to was the "experts" had never tried 12v and therefore couldn't answer the question. New or good used parts aren't always available and may not be in the future it is good to know alternatives in this case that cutting a new keyway is a better option than welding if it must be done.

babychadwick wrote: ↑

Fri Aug 25, 2023 12:06 pm

... it is good to know alternatives in this case that cutting a new keyway is a better option than welding if it must be done.

If by that you mean cutting a second keyway, then no, it's not a better option.

Curious why you say that Jerry. While a new keyway weakens the axle some, I wouldn't think it serious enough to cause failure on today's roads. Welding runs a risk of making the stub brittle. Not knowing what the axles are made of, that's just a concern not a fact. But still a risk a breakage. Your take.

As a farmer I would make it right. not all of us are idiots. but it would really be nice to see a Picture of said axle!
Bryant

RGould1910 wrote: ↑

Fri Aug 25, 2023 6:24 pm

Curious why you say that Jerry. While a new keyway weakens the axle some, I wouldn't think it serious enough to cause failure on today's roads. Welding runs a risk of making the stub brittle. Not knowing what the axles are made of, that's just a concern not a fact. But still a risk a breakage. Your take.

Richard,

As you say, a new keyway weakens the axle some. Enough axles break with just 1 keyway on today's roads. Removing more metal from an already old and worn axle puts it at risk. Don't misinterpret my comment. I wasn't suggesting welding was better. I wouldn't do either one.

My two cents. The first reply by John answered the original question accurately.

I wouldn’t consider a second keyway unless it was the last remaining axle and there was no bar stock available to make another.

There are several areas you have to check on an axle, bearing race areas, seal surfaces, taper, threads, keyway. Every axle I have taken out is unserviceable in at least one of those areas. Replacement axles are available and I can’t remember the last time I reused an original axle.

No part of the axle should be welded.


Andy

Interested in your reasoning why you wouldn't use an axle with a second keyway and why no part of an axle should be welded.

Ditto to Richard’s query.

The simple answer is that there is a high quality replacement part available to replace the damaged part.

Economics would be that, unless you are equipped and qualified to cut a new key way, a machine shop would probably charge close to the price of the known good replacement part. The new keyway would be removing precious material from a part that has already failed once.

I’m not a metallurgist, but I’m pretty sure that welding would have an adverse effect on a part with a hardness specification.

Since you would have to disassemble the unit for either of these operations I am confident that further inspection would find a shortcoming in one or more of the areas I previously mentioned.

Andy

Replacing with new is much safer. T axles are now over 100 years old, and fatigued. And many do fracture at the keyway, from loose hub.

Cutting a new key way 180 degrees away would induce more chance of fracture in such an aged used axle. MY 2 Cents.

So nice to have new quality T axles made in Taiwan, to the Ford print, and correct in all aspects for just $115.

Where and why could you have an old busted T axle welded-up and machined back for the little expense of a new?

Hypothetically speaking one could be on a long tour, say the one approaching in eastern Europe. One day you get something that warrants looking at the hub and a worn keyway is found. Do you abandon the tour? Stop and wait for a new axle to arrive? Or try to repair and keep going? I'm betting you could find a shop for a temporary repair. Although sometimes those temporary repairs outlast the car . .

FINALLY!
Dan said the word I have been waiting to hear…..fatigue! As a lifelong machinist and metallurgist with years of test experience, I can, without reservation, say that most if not all T catastrophic axle failures are the result of fatigue. The T axle is continuously flexing. It doesn't take much of a stress riser to induce the start of a fatigue failure millions of flex cycles later. The NOS TT axles that I recently modified and installed had a HORRIBLE stress riser as machined. The turning cuts on both ends of the axles contained a dead sharp 90 where the turned section met the unturned diameter. I removed the sharp corner with a .06”R and then polished these areas. No doubt, any PROPERLY done repair cost would exceed the purchase of a new axle.

I completely agree with Andy.

Chadwick, we need to differentiate between patch and repair. For a tour patch I would find a way to keep the key in place (gum, glue, whatever) and tighten the s**t out of the hub. Leave the cap off and check it often. By now it should be clear that welding is the worst option. As John mentioned in the first reply, you can fashion a stepped key if need be.


Andy

From Oldav8tor:
"FWIW - the buggered keyway is probably due to the axle nut being loose. I have seen dozens of axles ruined in this manner. Check you axle nuts - they need to be tight, really tight!"

The root cause of your axle keyway wear was a loose moving axle & hub.
The key isnt supposed to hold the wheel from turning. Its a proper fitting taper on both mating parts.
Ideally or correctly, You want to restore the taper fit before finish install. Thats done by lapping the axle & hub with lapping compound. That will take down the high spots in the tapers. The wheel fit is more important than the key fit.(think of your chuck as held in a drill press. taper fit, no key.) Then keep the nut tight. The axle nuts will need 2 or 3 torquings after a re-install, typically, as the high spots on the tapers wear down(unless you lapped the tapers), making the wheel loose again. Make checking the axle nut torque part of your annual service @ a minimum.

If I have understood your situation correctly. your "slightly" loose key could have been solved with a few prick punch hits on the key on the bottom edge to hold it securely to install the wheel & not have a loose key move inward to damage the outer grease seal.

I've welded one for a guy. He drives next to nothing and did not want to spend any money. It's still in the car. I would not tour with it but a parade would be fine.

Cordes_jeff wrote: ↑

Sun Aug 27, 2023 3:48 pm

I've welded one for a guy. He drives next to nothing and did not want to spend any money. It's still in the car. I would not tour with it but a parade would be fine.

Unfortunately, the next caretaker might be a gung ho driver
with a possible surprise waiting.

speedytinc wrote: ↑

Sun Aug 27, 2023 4:06 pm

Cordes_jeff wrote: ↑

Sun Aug 27, 2023 3:48 pm

I've welded one for a guy. He drives next to nothing and did not want to spend any money. It's still in the car. I would not tour with it but a parade would be fine.

Unfortunately, the next caretaker might be a gung ho driver
with a possible surprise waiting.

No worries. A new t owner will be told the horrors of babbitt washers and have to tear it apart regardless. . .lol

I agree with mike and would prefer a new part. I was going to post something about stress risers if the machining doesn't properly radius any cuts. Think crankshaft journals.

babychadwick wrote: ↑

Mon Aug 28, 2023 8:56 am

speedytinc wrote: ↑

Sun Aug 27, 2023 4:06 pm

Cordes_jeff wrote: ↑

Sun Aug 27, 2023 3:48 pm

I've welded one for a guy. He drives next to nothing and did not want to spend any money. It's still in the car. I would not tour with it but a parade would be fine.

Unfortunately, the next caretaker might be a gung ho driver
with a possible surprise waiting.

No worries. A new t owner will be told the horrors of babbitt washers and have to tear it apart regardless. . .lol

The new owner wont have the forum as we now know it.
Bots will have replaced all of us.