buckeyefarmer
Epic Contributor
Wow, I thought it was bad when i snapped a 1" axle on my riding mower last yr.View attachment 604414
My neighbor came down this morning and helped me tow the tractor up to the garage where it could be worked on. He drove the Kubota side-by-side while I steered and braked the tractor. It took several attempts to find a slope shallow enough for the little Kubota to pull the bigger one up, but once on the concrete, we did just fine. He stuck around long enough to get the thing up on jack stands and help remove the wheel. It pulled right off without removing any fasteners or clips, with a foot long piece of axle still attached. I'm very fortunate it didn't decide to come off during yesterday's mowing, or during the trip backing/coasting down the driveway.
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The gear case came loose with a couple whacks of a dead blow hammer and come careful prying with a putty knife. Another quart or so of fluid came out the joint, that was in addition to the four or so gallons I'd already drained from the main transmission case. Sadly, I'd just replaced the fluid less than 50 hours previously. Peeking through the center of the big reduction gear is the stub end of the axle.
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The wheel flange/axle and the stub and bearing. These are not small parts.
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The smooth nature of the shear faces tells me that this is a fatigue fracture that had been propagating for a long time. It started at the bottom of a groove machined into the axle causing a stress raiser that focused the twisting forces at the notch. The notch was probably put there to provide a place for the cutting tool when the threads were cut on a lathe. It's a common practice to use such a notch, but hopefully the bottom of the notch is "U" shaped, not the square corners that Kubota used on this axle. This is a design and/or manufacturing defect that very nearly resulted in severe bodily injury or death.
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It took 15 years and 2193 hours for this axle to break. But that's assuming this is the first time it happened. The gear case shows signs of having been removed before, and if it was to replace the axle, I'm wondering what shape the one on the left side is in. It's definitely time to find a new home for this tractor before it has a chance to take another shot at me. And find a tougher machine that can take the abuse of the hills, rocks, and trees here, probably a tracked skid steer.
I snapped a back axle on a dump truck years ago.