Broke my B26TLB rear axle shaft

[gstrom99]

I will guess the cause was the tire ballast was not removed when the backhoe was on. OP indicated tires were loaded in post #8.

I no longer own my TLB but the manual says for the B26tlb the rear ballast (loaded tires) should be removed when the BH is attached. So maybe a rear end overload situation??

I think tire ballast doesn't put much/any stress on the axle. A backhoe sure does.

I've never liked the idea of one on a small(ish) tractor, but they sure seem useful, until something breaks...

 

[MapleLeafFarmer]

I've had my B26 for about 10 years give or take and it had loaded tires when I got. I have never unloaded them but I have used the three point hitch a lot bush hogging and such.

kinda same on my end.....
Kubota warns though that on B26tlb and many other models they do not want the BH on at the same time the tires are loaded.
So if I choose to use my BH then they want the ballast from the tires removed.
A choice I had to make or risk over weighing the rear end so I went a different route. BH was enough weight when on. When BH off then a 3pt implement was used for weight (i had a nice/handy/compact logging winch that fit the bill)
If I didn't have a BH I too would consider filling rear tires.

 

[rScotty]

kinda same on my end.....
Kubota warns though that on B26tlb and many other models they do not want the BH on at the same time the tires are loaded.
So if I choose to use my BH then they want the ballast from the tires removed.
A choice I had to make or risk over weighing the rear end so I went a different route. BH was enough weight when on. When BH off then a 3pt implement was used for weight (i had a nice/handy/compact logging winch that fit the bill)
If I didn't have a BH I too would consider filling rear tires.

I don't think Kubota is concerned about the ballast of the filled tires as much as the effect of that much weight being held out at a distance from the axle support bearing - which is what we have when the stabilizers raise the rear tires off the ground. With the tires lifted, all that weight is now just hanging out there unsupported.

Then add in the quick high axle stresses from operating the backhoe - particularly the bouncing around we get when digging though tough soil.... and that combination of weight and impulses may be what broke that axle.

The OP's original photo shows a typical break right where we would expect from too much combined bending stress.

rScotty

 

[civilian]

will you remove the ballast now or the backhoe to match up with manufacturers weight warnings or going to continue to run with both?

cheers

Nope

 

[Shawn T. W.]

I don't see how 100 pounds of ballast would break an axle, if Kubota is building the axles that close to its breaking point, I'd be very surprised to not see most all axles break!

 

[rScotty]

I think tire ballast doesn't put much/any stress on the axle. A backhoe sure does.

I've never liked the idea of one on a small(ish) tractor, but they sure seem useful, until something breaks...

I don't see how 100 pounds of ballast would break an axle, if Kubota is building the axles that close to its breaking point, I'd be very surprised to not see most all axles break!

I don't think the problem is the ballast or the weight of the backhoe. It's all in how the backhoe is operated.

Anyone who uses a hoe knows how by using downforce on a backhoe bucket the hoe can easily pick up the back of the tractor - which greatly increases the penetration of the backhoe bucket in hard ground. It's tempting to work the hoe that way, because it really speeds up the digging - especially when cutting through rocks & roots. But everytime I do that, with every bucketful I can feel how I'm really beating up the whole machine. Ballasting the tires just adds even more unnecessary stress out on the ends of the axles.

Kubota obviously knows that, and knows how strong their tractors are or aren't. Take a look at the optional equipment Kubota sells for their TLBs, some models allow wheel weights & some even allow multiple wheel weights with a backhoe. Other models apparently don't.

These are inexpensive homeowner machines we are talking about, not commercial duty backhoes. Of course they have limits. They are still handy tools, in spite of the limits.
Luck,
rScotty

 

[woody]

What rScotty says makes sense, so my question would be with the outriggers down do I raise the rear wheels off the ground completely or try to get the majority of the weight off the ground and leave the tires barely touching?
Of course that would be according to the ground situation.

 

[shooterdon]

What rScotty says makes sense, so my question would be with the outriggers down do I raise the rear wheels off the ground completely or try to get the majority of the weight off the ground and leave the tires barely touching?
Of course that would be according to the ground situation.

Don't think is a wise way to operate the BH on a tractor. The outriggers are stabilizers. Lifting the tractor is going to put a lot of stress on it. A TLB is built a lot stronger.

 

[LouNY]

On my little Kioti CK2620 the manual says to use the hoe to lift the tractor then place the outriggers. So the outriggers are not lifting the tractor just stabilizing it.

 

[grsthegreat]

Im confused… how does your homeowners insurance pay for a broken tractor axle?

 

[dodge man]

Keep in mind the op has a B26. It’s suppose to be a purpose built machine for a backhoe and FEL, much stouter than your typical subcompact tractor. I’m not sure if it’s a true construction grade machine or not.

 

[rScotty]

What rScotty says makes sense, so my question would be with the outriggers down do I raise the rear wheels off the ground completely or try to get the majority of the weight off the ground and leave the tires barely touching?
Of course that would be according to the ground situation.

With a decent subframe and NO extra tire weights, I like to operate our hoes with the outriggers holding the tires completely clear of the ground. That's just me. The whole rig feels more stable that way.

Now if the tires are filled or weighted I might still raise the tires clear of the ground, but I'd be aware that Kubota is apparently warning us against doing that. Stress failures come from adding too many stresses together at the same time. I gotta believe Kubota knows, but i also want to do work.
My own compromise would be to be more careful when using the hoe with loaded tires held up off the ground. I'd slow down the hoe so the rig isn't jumping, bouncing, or slamming around.

For sure I'd avoid the temptation to use so much boom & bucket downpressure that the outrigger pads come off the ground or slide too much.

As much work as TBNers do, we rarely hear about a broken axle. Just be reasonable....

rscotty

 

[rScotty]

Keep in mind the op has a B26. It’s suppose to be a purpose built machine for a backhoe and FEL, much stouter than your typical subcompact tractor. I’m not sure if it’s a true construction grade machine or not.

The B26 has a nice backhoe and loader. I like 'em. But all the smaller TLBs are homeowner type and they do have limitations. On the other hand, they are also light enough to use on a lawn - maybe even mow some grass.... things which a heavy construction grade TLB doesn't do so well.

The M59 and M62 are Kubota's semi-construction grade TLBs. Both of those models can handle quite a bit of extra wheel weight. In fact, they can be ordered with Kubota's own wheel weight and bolt kit.
Using up to 3 of Kubota's cast iron weights per side.
Part # LM8124.

"Wheel Weights (Max. 3 weights per wheel)
Set of 2 (103 lbs. each side, 200 lbs/set)
Requires (1) LM8125 and M8121 for 2nd / 3rd set"'

 

[rScotty]

On my little Kioti CK2620 the manual says to use the hoe to lift the tractor then place the outriggers. So the outriggers are not lifting the tractor just stabilizing it.

You are right, Lou. I'd forgotten about that type hoe. Is it a 3pt hoe? It is true that some 3pt hoes have stabilizers that work like that. I should have remembered that - we had one many years ago.

To mount the 3pt hoe we would hook up the PTO pump and then use down pressure on the the hoe bucket to lift the hoe into position.
Then then lower the vertical stabilizers on each side until they touched the ground...and only then would we actuate the 3pt lower arms which would rise up to trap a special round piece of very thick wall pipe between the stabilizer arm and the backhoe frame. Pinching the pipe that way between arms and frame provided some stability to the 3pt hoe. But it also put a huge load on the 3pt mounts.

There might even be other small hoes that work similar because of having stabilizer cylinders that are too small to lift the tractor, or maybe were built without hydraulic load check valves in the stabilizer control valves.

But those types must be getting rare. Most TLBs and frame mount hoes I see have outrigger/stabilizers that will easily lift the rear of the tractor & wheels off the ground - along with load checks that prevent the outriggers from collapsing.
Thanks,
rScotty

 

[LouNY]

You are right, Lou. I'd forgotten about that type hoe. Is it a 3pt hoe? It is true that some 3pt hoes have stabilizers that work like that. I should have remembered that - we had one many years ago.

To mount the 3pt hoe we would hook up the PTO pump and then use down pressure on the the hoe bucket to lift the hoe into position.
Then then lower the vertical stabilizers on each side until they touched the ground...and only then would we actuate the 3pt lower arms which would rise up to trap a special round piece of very thick wall pipe between the stabilizer arm and the backhoe frame. Pinching the pipe that way between arms and frame provided some stability to the 3pt hoe. But it also put a huge load on the 3pt mounts.

There might even be other small hoes that work similar because of having stabilizer cylinders that are too small to lift the tractor, or maybe were built without hydraulic load check valves in the stabilizer control valves.

But those types must be getting rare. Most TLBs and frame mount hoes I see have outrigger/stabilizers that will easily lift the rear of the tractor & wheels off the ground - along with load checks that prevent the outriggers from collapsing.
Thanks,
rScotty

This is the factory's expensive little hoe that has it's own sub frame under the tractor. Mine is run from the tractor rear remote that detents into the flow position. To remove or attach you remove a couple of pins then using the hydraulics get every thing loosened and aligned using the hoe and the stabilizers, once the sub frame clears the tractor mounts you can lower it and relax the hydraulics to disconnect and drive away.

 

[civilian]

The way I use the B26TLB, is usually set outriggers down to stabilize tractor. Not necessarily to raise rear tires off the ground. But I will level the tractor if on uneven ground, minimum to get what I need. Also I am in clay soil, no rock hard that I have to pound into the ground. No digging in frozen winter soil. Also this is Kubota's line of full frame design for the backhoe and the loader arm frame. Most youtubes I found on changing rear axles very easy. Pull off the axle housing and change axle. B26TLB was basically completely disassembled. 24 hours to replace my rear axle. Engine, hydrostat, axles had to be lifted out of the frame, after removing backhoe (with no hydraulics), cab, operator floor, loader arms. Most of the hours on the unit are loader work, not backhoe work.

I have looked at a larger tractor than the BX2230. But I don't want to replace the B26TLB with a B or LX and put a 3pt backhoe on it. The B26TLB is a much stronger build piece of equipment. Jon

Edit: The frame on the B26TLB is a full wrap around frame. It is an assembly from in front of the engine supporting it and around to the backhoe which is connected to the frame. The loader arm frame is also designed into the frame. The backhoe is not 3pt mounted or subframe mounted.