Kubota rear axles/differentials

[Danner]

The tractor did not overload the 3-point, the operator did.

Quoted for truth.

 

[juadro]

Slowzuki, failure started over a year ago. At that time, I was hauling a tank of water on a 3-point fork lift over somewhat rough surfaces (since the front axle was "floating" on the ground, an acquaintance said if I was relying on skid-steering I was overloading). I noticed a crack starting, on the top of the hydraulic cylinder case, above the lift arms' shaft, and parallel to the shaft. After consulting several knowledgeable welders/etc., I put a metal strap "bridge" across the fault line. To anchor the bridge I used two original bolt locations - and went on happily for a year not even thinking about the repair; and, ceased hauling "overloads". Then, two days ago, I was using the post hole digger. Although the auger was turning, in other words, it had not screwed itself into something, the Kubota wasn't pulling it out of the hole - as deep as the auger is long. Since the loader bucket was not attached, I assumed that's why the front end was up in the air! Soooooooo, I pushed down on the front (I weigh-in around 190 pounds.) and heard the awful CRACK. (My "bridge" ripped into two, along with the case). My point/wish is: when an operator, as MyJoBota points out, is capable of (over-)loading machinery, it would be nice if the weakest link in the chain was not an integral part of the machinery! Slowzuki, thanks for the heads-up ... I'll cancel any plans to buy a back-hoe attachment.

 

[slowzuki]

If you use a backhoe, get a subframe type. The problem with the top link in compacts of that age is they use the original ferguson type linkage, the piston inside that area puts a lot of strain on the casting, as well tension loads on the top link pull on it as well.

Driving on rough terrain will put higher loads than what you can actually pick up on the area too. There is not relief valve on that piston.

The new Kubotas use external cylinders and a beefy plate / bracket in this area and seems to have solved this problem.

Its also possible your relief valve for lifting has been turned up or shimmed causing your hitch to be able to lift more than it should.

 

[juadro]

Slowzuki, thank you for the overview of this kind of problem/issue. Your reply satisfies my original reason for posting. I'm sending a link to this thread to another New Member who posted with what sounds to be a similar problem/issue. In retrospect, I think I could still be in business with my Kubota if I had "bridged" over the failure with a thicker plate, beefy, in your terms:thumbsup:!

 

[Baby Grand]

With the idea that bending an axle would fracture an imaginary extension to the casing ... what do you experienced folks say about this situation? My 17hp Kubota managed to (over-)load it's 3 point system to such an extent that it now has a ruined [fractured in two] hydraulic cylinder case and a badly damaged top rear edge on the differential case; the edge damage is a consequence of the hydraulic cylinder case getting ripped off of the tractor.
Looking at the damage causes me to wish the tractor had been designed so that an (over-)load would break the lift arms rather than allowing them to transfer the (over-)load to their shaft which then fractured the hydraulic cylinder case.

I would say that even when overloaded to the point of failing the TPH, the axles maintained structural integrity.

 

[LD1]

Were you using a logging winch or 3 point backhoe? Common damage from that type of use on compacts.

+2

JUADRO: so how exactally did that happen???

EDIT: Nevermind. I see you already answered it.