Am I the first to brake a BX23 axle???

[irwin]

I'd imagine with diff locked and dually wheel set up, that would put tremendous stress on the axle . Two wheels on each side trying to hold the surface at the same time

..hope you have better luck now, ..

...tim

 

[SPYDERLK]

Today I think I found out what broke my axle...
I was using the Kubota today and I noticed a scuffling sound when i was on the gravel making a turn... so I watched the back wheels and one was sliding around and not turning... My differentiel lock was stuck... The pedal was not coming back up to the top... A little WD-40 and it was like new again... With the weight of the hoe and my duels and working on hard ground with the differentiel lock on is not good...

What do you think??? Was that my problem ???

I would venture that it had virtually nothing to do with your diff loc. That would have caused twist failure at the thinner cross section. What you have is bend flexure initiating and propagating a crack in a reduced section just inside the outer bearing - just where yould expect max bend stress. Its the extra bend leverage on the axle from the duals and the added weight of the hoe. Consider yourself lucky if the other one doesnt go soon. Drive gently.
larry

 

[Kevin Beitz]

I would venture that it had virtually nothing to do with your diff loc. That would have caused twist failure at the thinner cross section. What you have is bend flexure initiating and propagating a crack in a reduced section just inside the outer bearing - just where yould expect max bend stress. Its the extra bend leverage on the axle from the duals and the added weight of the hoe. Consider yourself lucky if the other one doesn't go soon. Drive gently.
larry

I don't believe that... This happen to fast... It sounded like a small explosion when the axle snapped... If it was a bend stress it to my opinion would have broke with almost no sound... It had to be under a lot of torque at the time of the snap...

 

[Bob_Young]

If you operate that thing on a side hill, Kevin, it would be wise to use the ROPS and the seat belt....religiously.

 

[Kevin Beitz]

Rops yes... Seat belt.... Never... Last year when I rolled my other Kubota over I would be dead If I had my belt on... If its going over I'm leaving...
I'm a forklift instructor and I was told to ride it out and to teach it this was...
I strongly disagree...

 

[SPYDERLK]

I don't believe that... This happen to fast... It sounded like a small explosion when the axle snapped... If it was a bend stress it to my opinion would have broke with almost no sound... It had to be under a lot of torque at the time of the snap...

Ok. So why didnt it break at the thinnest place instead of a thicker place where bending stress is much higher?
larry

 

[DmansPadge]

If the differential was locked you would have known it. You would have went straight whether you where turning the steering wheel or not.

 

[design]

Kevin,
The issue appears to be a fatigue failure on the axle. I would need to see the parts closer for a better failure analysis. (Undergrad degree in metallurgy) Three reasons come to mind:

1. Having duelly's on your rear axle significantly lengthens the cantilever beam and increases the load to the inside of the outermost wheel bearing section of the rear axle. I just ran the calculations for my L2900 before getting wheel spacers for the rear wheels. A small change in the tract width (2" per side) drops the load capability of the rear axle on a L2900 by 50%. This change also really affects the fatigue life of the parts. If you put duelly’s on your machine, the change to the track width was much greater than the 2 inches that I just ran calculations for on my tractor. The old tract width was center of tire to center of tire on the rear axle. With the duelly’s, the new tract width is center of the two tires to center of the two tires. I would consider the other axle to be potentially damaged goods at this point and would be very careful in situations where injury could occur in that axle would fail.

2. Carrying to much load on the rear axle, another possible cause to the fatigue issue discussed above

3. Manufacturing issue on the rear axle.

 

[SPYDERLK]

Kevin,
The issue appears to be a fatigue failure on the axle. I would need to see the parts closer for a better failure analysis. (Undergrad degree in metallurgy) Three reasons come to mind:

1. Having duelly's on your rear axle significantly lengthens the cantilever beam and increases the load to the inside of the outermost wheel bearing section of the rear axle. I just ran the calculations for my L2900 before getting wheel spacers for the rear wheels. A small change in the tract width (2" per side) drops the load capability of the rear axle on a L2900 by 50%. This change also really affects the fatigue life of the parts. If you put duelly’s on your machine, the change to the track width was much greater than the 2 inches that I just ran calculations for on my tractor. The old tract width was center of tire to center of tire on the rear axle. With the duelly’s, the new tract width is center of the two tires to center of the two tires. I would consider the other axle to be potentially damaged goods at this point and would be very careful in situations where injury could occur in that axle would fail.

2. Carrying to much load on the rear axle, another possible cause to the fatigue issue discussed above

3. Manufacturing issue on the rear axle.

Yes, exactly. I appreciate your seconding this truth. My original post and Kevins response make me think he will have to go a little deeper into the mechanics of failure and the relationship of various forces to it. Given the level of abuse this setup causes on the axle, the manufacturing defect issue as a cause is less likely.
larry

 

[Kevin Beitz]

I really don't like this tractor without the duels... It tips so easy... Very easy... So whats the difference if I load my tires or use wheel weights??? How much stress will that put on me axles???