Rear axle crack

[Adam]

Cracked because of work hardening from a hub that was loose on the taper.

[Jerry VanOoteghem]

I can't get any kind of perspective with such a close-up shot. Can you post a picture from a bit further back and maybe point to the "crack" with a pencil?

[Kevin Pharis]

Many axle cracks start from the sharp internal corners of the keyway…

[Dan Hatch]

That is why someone invented the Magaflux machine. Take it to a machine shop and get it checked. Be safe not sorry. If it is cracked it will cost a lot more to fix damage it will do than to check it. I know!

[Scott_Conger]

All things considered (and considering the groove cut by the Hyatt bearing), since you are of a mind to replace the axles, I'd say there is really no other choice. The number of axles broken right at that bearing groove is pretty surprising...I think even more likely than your crack propagating into an accident, quite frankly. Regardless, they've given 100 years of service without incident and it looks like it's time to retire them.

[CudaMan]

When you first posted, I thought you were talking about a crack somewhere in the axle housing. Now that I see it's in the axle shaft, by all means replace the axle shaft. It will fail eventually, probably sooner rather than later, as I found out the hard way on my 1924. Luckily, the wheel didn't fall off and I run AC brakes, so I still had brakes.

[CudaMan]

I am not aware of any current issues with improper hardness on axle shafts provided by the vendors, does anyone know differently?

Some axle shafts are offered with 1/16 inch extra length to help offset wear on the taper of old rear hubs, which can cause the wheel to run too far inboard. Whether you choose the stock or slightly longer length is up to you.

I got my new axle shafts from Chaffin's. I sent them my axle gears, keys, and keepers ahead of time and they pressed the gears onto the new axles before they sent them to me.

[NoelChico]

I had an axle break at the same place on last year's Ohio tour. Fortunately, we were attempting to pull from a stop sign, not cruising at 35-40 mph. I'd replaced these axles 15 years ago and noted grooves from the Hyatte bearings at the break and on the other axle as well. I believe there were issues with new axles then, but I've not heard of any now. It makes me consider safety hubs.

[Art M]

The axle crack might be caused by surface decarb due to grinding burns or due to some other manufacturing error. I have seen a lot of these occurrences.

Art Mirtes

[RajoRacer]

You don't want to run any axle that has been scored !

The new axles are very good - only issue to watch for is the keyway - a bit too tight for "off the shelf" 1/4" key stock.

[TXGOAT2]

Better tight than too loose. It's easy to dress keys on a new double cut file. Don't over-do it.

[Jerry VanOoteghem]

Yep, I'd consider replacing it, based on the scored taper alone.

[Oldav8tor]

I've helped a bunch of guys get their cars going and one of the most common problem is damaged rear axles that need replacement. They're scored, cracked, keyways wallowed out, etc. Most of the damage can be traced to not keeping the rear axle nuts tight. By all means I would suggest replacing your axles. You might want to consider replacing the outer hyatt bearing with floating safety hubs, which transfer much of the load to the rear axle tubes and in the unlikely event of an axle failure, won't let the wheel fall off the car.

Here is an earlier thread on rear axles and the problems from loose axle nuts. You might want to check it out. https://mtfca.com/phpBB3/viewtopic.php?f=2&t=30874

[AndyClary]

It’s rare to pull out an original axle and be able to say it is good in all aspects. For instance the one in the photo has grooving and the taper looks pretty rough. I’d put money that it wouldn’t pass muster in the bearing wear area and inner seal. The new axles are well made and cheap insurance.

Andy

[Tadpole]

I recently found out my rear end has a crack in it as well, thankfully the doctor told me everyone's does.

[Jerry VanOoteghem]

I recently found out my rear end has a crack in it as well, thankfully the doctor told me everyone's does.

That crack is only a problem when the seal fails.

[tdump]

Well sadly the T axle is slightly to large for correct tournament size horse shoe stobs so looks like scrap axle rod sadly

[kmatt2]

I am a Ca licensed land surveyor. Old worn out Model T rear axles make nice lot corners. They also make nice tree stakes for keeping that new tree growing up straight and tall. Keep the axel gear if it is still good for the new axel or later reuse.

[tvw]

How do you affix your brass tag to the axle Kevin?
CO PLS here.

[CudaMan]

I cut my old axles into various shorter lengths and use them as tooling for my hydraulic press.

[Norman Kling]

It also makes a good driver wheel puller. You back off the nut half way from the axle on the car and thread in the broken axle till it is tight with the axle. Then jack up the opposite side and hit with a heavy hammer.
Norm

[Kevin Pharis]

Old worn out Model T rear axles make nice lot corners. They also make nice tree stakes for keeping that new tree growing up straight and tall

They also make great wench anchors when there are no trees around

[kmatt2]

Yes Jeff , ( tvw ) , the brass PLS number tag is a problem. I have been able to use stainless wire in the lock key groove to wire the tag to axle but generally pre drill and tap the axle for a tag set screw using index hole in the geared axle end, less the gear. Most of the time these days I just use the common half inch pipe with yellow plastic number tag. Happy surveying to you Jeff.

[John Illinois]

I also check the taper in the hub .It needs to make good contact with new axle.

John

[Sean Butler]

I remember seeing them used for circus tent stakes.

[mbowen]

They also make great wench anchors when there are no trees around

Is that in case she tries to run away? (According to dictionary.com: wench: noun, a country lass or working girl)

Gotta love homonyms!

[Kevin Pharis]

They also make great wench anchors when there are no trees around

Is that in case she tries to run away? (According to dictionary.com: wench: noun, a country lass or working girl)

Gotta love homonyms!

Only because a cage would be inhumane