Repairing a broken axle shaft - GIF

[Altair]

Repairing a broken axle shaft in South Asia.




Previously:

Building a dump truck in South Asia - GIF
Making truck wheels - GIF
Manufacturing truck brake shoes - GIF
Casting and machining truck brake drums - video
Casting crankshafts - GIF

[Frank S]

It broke once due to being over torqued. now it has 2 heat effected areas with only about 60% of the cross section of the shaft fused back together by weld. the piloted section is just a tap fit even normalizing the shaft and re heat treating it will never be as strong as original. Granted I have welded axle shafts back together myself knowing full well it was only a temporary fix until a replacement could be obtained

[hemmjo]

I am surprised he was able to turn that. Aren't axles pretty hard. I have some steel in my collection I have collected over that years that I cannot turn. It is just too hard for my equipment. Some are pins from excavating equipment, a few broken axles, one very nice 2 1/2" diameter x about 30" long hydraulic cylinder rod.

"Some day" I hope to get a broken ceramic kiln I have put back together to use for heat treating, annealing, etc. So for now my collection of steel lays patiently waiting to become useful again.

[Frank S]

I am surprised he was able to turn that. Aren't axles pretty hard. I have some steel in my collection I have collected over that years that I cannot turn. It is just too hard for my equipment. Some are pins from excavating equipment, a few broken axles, one very nice 2 1/2" diameter x about 30" long hydraulic cylinder rod.

"Some day" I hope to get a broken ceramic kiln I have put back together to use for heat treating, annealing, etc. So for now my collection of steel lays patiently waiting to become useful again.

In general you are correct but mostly axles are tough rather than being just hard. the splines usually have more surface hardness than the rest of the axle. It's called case hardening. Annealing makes things easier to turn and when finished must be heat treated and tempered.
One good way to tell if you can turn the stock that you have without the need to anneal is to use a file if a few strokes will cut a grove then you can turn it if the file can't even scratch it then shove it in a forge or oven or use a rose bud torch. Even if you can only bring the surface temp. up to a 1000°f and allow it to slowly cool will reduce the case hardening somewhat.
Some hydraulic cylinder rods particularly Caterpillars have such a deep case hardening that they defy reason. Excavator pins will be work hardened as much as having an original hardness the bilby layer can become like glass. you have to get under it before turning is going to get any easier.
When I refurbish pins I will usually have to grind them before building them up0 and turning back to size then heat until a magnet wont stick quench reheat and pack in heated lime until cool/
In the past I have had customers tell me my refurbished pins would last longer than the new ones. 'THEY WON'T' if they seem to have a greater longevity it is because the customer learned what a grease gun is for

[Philip Davies]

I am surprised he was able to turn that. Aren't axles pretty hard. I have some steel in my collection I have collected over that years that I cannot turn. It is just too hard for my equipment. Some are pins from excavating equipment, a few broken axles, one very nice 2 1/2" diameter x about 30" long hydraulic cylinder rod.

"Some day" I hope to get a broken ceramic kiln I have put back together to use for heat treating, annealing, etc. So for now my collection of steel lays patiently waiting to become useful again.

Depends how much heat treatment you want to do, but ordinary house bricks can often stand repeated heats. The base and sides of my forge are of loosely laid, salvaged hand thrown bricks.