B26 TLB - Broken rear axle

[pcproffitt]

About ten days ago while repositioning my B26 TLB digging a trench, one of the rear axles broke. The break was just inside the transmission case. This means that a lot of UDT2 hydraulic fluid was dumped on the ground. For reference, this is a 2011 B26 TLB with 943 hours. I bought it used in 06/2021 when it had 842 hours.

At the time of the actual break, I was simply backing the tractor. The stabilizers were up. While doing the digging with the backhoe earlier the stabilizers were down.

The reason for my post is to see if anyone has had anything similar happen. My local dealer (Mason Tractor Company in Norcross, GA) has the tractor. I am hoping to meet with them in a few days to discuss moving forward.

Below is a link to an end-on image of the broken axle (as well as an attached file image). I am not a metallurgist, but this doesn't look like just a stress break. To me, it seems this axle may have had issues from the factory. I've asked my dealer to consult with Kubota on this. But the service manager doesn't think Kubota will be any help.

One complicating factor is that in 07/2021 (about 100 hours runtime ago) I installed a pair of 4" rear wheel spacers (from motorsport-tech.com) to improve stability. My property is not at all flat. The wheel spacers really improved the tractor's stability. But, they did push the rear wheels out 4" on each side. I know this would increase the stress on the axles, but it seems that Kubota has offered some sort of wheel spacers at some point in time. If true I would think the stock axles would not have been overly compromised by adding these wheel spacers.

Among my many questions are:

1) Would / should Kubota consider replacing the broken axle and associated parts (bearings and seals and fluids)?

2) I feel I should consider replacing both the rear axles not just the one, suggestions?

Thanks, Paul

Link to a photo of the end of the broken axle: Broken axle (end-on) photo

 

[JimmyJazz]

I would not have the balls to expect them to absorb the loss given the circumstances. If this were a known issue you would find plenty of evidence of it via Google. Not that you cant try. I would reconsider using the spacers after it is fixed. I will defer to others on whether or not to replace both rear axels. Good luck.

 

[hagrid]

I am not a metallurgist, but this doesn't look like just a stress break.

View attachment 104817

This appears to be a ductile fracture that transpired in short order due to the lack of oxidation that would suggest a long period failure.

It is plain to see the difference in microstructure edge to center owing to the transverse position of the evidence.

Whilst I cannot preclude a long or protracted period to the fracture, the evidence, as presented, suggests a short period of cycling to ultimate failure.

The area at 3 o' clock represents the final failure. Note the shoreline features directly opposite at 9 o' clock. These likely represent the origin direction of the initial failure.

Take note of where the fractures are pointing... that single point is a prime candidate for the initial failure.

 

[Henro]

This appears to be a ductile fracture that transpired in short order due to the lack of oxidation illustrating a long period failure.

It is plain to see the difference in microstructure edge to center owing to the transverse position of the evidence.

Whilst I cannot preclude a long or protracted period to the fracture, the evidence, as presented, suggests a short period of cycling to ultimate failure.

The area at 3 o' clock represents the final failure. Note the shoreline features directly opposite at 9 o' clock. These likely represent the origin direction of the initial failure.

View attachment 104830 This

Take note of where the ductile fractures are pointing... that single point is a prime candidate for the initial failure.

looking at the photo, I would’ve guessed the initial fracture started over in the 3 to 4 o’clock area, and the final break occurred towards the 9 to 10 o’clock area…

This is only because the metal surface in the 9 o’clock area is freshly shiny, while the metal surface over on the 3 o’clock area looks much less fresh and shiny.

I’m certainly not claiming to know anything, and just stating my initial impression.

 

[hagrid]

I am confident declaring the failure mode as "reverse bending".

 

[GreensvilleJay]

sorry but....I can see that..
The BIG problem IS the wheel spacers. Unless Kubota offered them as an option for your tractor, it'll become a 'contest', with them arguing that the spacers you put on 'put undo stress' onto the axle, and was the cause of the failure. For the first +-800 hrs of use, it was fine, then 100 hrs of spacers, bang, it broke.

Unless you can show say 6-12 other ,same model tractor WITH 4" spacers , running fine with over 100+ hrs, I think you're outta luck and will need a at wallet for the repair.

 

[hagrid]

looking at the photo, I would’ve guessed the initial fracture started over in the 3 to 4 o’clock area, and the final break occurred towards the 9 to 10 o’clock area…

This is only because the metal surface in the 9 o’clock area is freshly shiny, while the metal surface over on the 3 o’clock area looks much less fresh and shiny.

I’m certainly not claiming to know anything, and just stating my initial impression.

The dark patch at 3 o' clock represents steel in tension, being torn apart and letting go at grain boundaries. That's why it's dark.

The light areas are the grains being sheared in half as opposed to being pulled apart.

 

[Henro]

The dark patch at 3 o' clock represents steel in tension, being torn apart and letting go at grain boundaries. That's why it's dark.

The light areas are the grains being sheared in half as opposed to being pulled apart.

I don’t see any signs of rust or corrosion that might indicate that the brake might have been occurring over time.

Was this failure likely a catastrophic immediate event?

Wheel spacers certainly did not do anything to delay the break happening. They only enhanced the opportunity for it to happen. Another unknown is how the tractor was used/abused in the 800+ hours before the OP bought it.

 

[hagrid]

I don’t see any signs of rust or corrosion that might indicate that the brake might have been occurring over time.

Was this failure likely a catastrophic immediate event?

This appears to be a ductile fracture that transpired in short order due to the lack of oxidation that would suggest a long period failure.

Whilst I cannot preclude a long or protracted period to the fracture, the evidence, as presented, suggests a short period of cycling to ultimate failure.

I think we agree on that point?

 

[mikester]

Here's how it will probably play out:
OP: My tractor broke because it was defective
K: No

 

[pcproffitt]

Many thanks to all the respondents to date. Particularly to 'hagrid' for the metallurgical commentary.

I'm under no illusion that Kubota would offer up anything. But as Jimmyjazz implied, it doesn't hurt to ask.

My conclusion from the comments is that I will forgo the wheel spacers after having both axles replaced. An expensive lesson! While the wheel spacers are great for stability on non-flat ground, they appear to be particularly inappropriate for use with a backhoe unless the stabilizers are rigorously used to completely elevate the rear wheels. Suffice it to say I have not been that rigorous. Another lesson learned! My guess is that ANY lack of use of the stabilizers with the backhoe could also result in a broken axle even without wheel spacers.

 

[Henro]

Many thanks to all the respondents to date. Particularly to 'hagrid' for the metallurgical commentary.

I'm under no illusion that Kubota would offer up anything. But as Jimmyjazz implied, it doesn't hurt to ask.

My conclusion from the comments is that I will forgo the wheel spacers after having both axles replaced. An expensive lesson! While the wheel spacers are great for stability on non-flat ground, they appear to be particularly inappropriate for use with a backhoe unless the stabilizers are rigorously used to completely elevate the rear wheels. Suffice it to say I have not been that rigorous. Another lesson learned! My guess is that ANY lack of use of the stabilizers with the backhoe could also result in a broken axle even without wheel spacers.

Wonder if your wheel spacers would fit my B2910? Might be interested in them if they would...perhaps we could work out something if indeed you decide you do not want them any more...and by chance they would fit my tractor.

I think the tractors are about the same size. I don't use the backhoe on mine since I got an old mini excavator. But after tipping my B2910 on its side about ten years ago, in a situation where I would never have expected it to happen, I do feel the need for wheel spacers every time I use that tractor.

 

[pcproffitt]

Wonder if your wheel spacers would fit my B2910? Might be interested in them if they would...perhaps we could work out something if indeed you decide you do not want them any more...and by chance they would fit my tractor.

I think the tractors are about the same size. I don't use the backhoe on mine since I got an old mini excavator. But after tipping my B2910 on its side about ten years ago, in a situation where I would never have expected it to happen, I do feel the need for wheel spacers every time I use that tractor.

You could ask the folks at motorsport-tech.com where I purchased the spacers. Their website doesn't provide a comparative capability, just a selection of vehicle. If the wheel sizes are the same (which I suspect they are), then there might be a chance the spacers would be the same.

I haven't decided whether to let go of the spacers yet. That will be determined after further discussion with the dealer and (if possible) Kubota. If I do decide to sell them, you are first on the list.

 

[Smokeydog]

I have BroTek 2” wheel spacers on my B26. 600+ hours and 7 years. Greatly helped on my hillside farm.
Tractors need spaced tires for their intended use.

4” spacers may be suspect. Over jealous tie down while trailering on pneumatic tire equipment puts high loads on axles too.

Respect analysis on why the axle broke but from what is still unknown. Improper outrigger support while digging? 4x4 on hard surfaces? Improper use of diff lock? Used equipment is always a guess.

Haven’t heard of another B26 axle breaking. Often used in rental because they can take abuse. Will be thinking about this.

 

[Henro]

I have BroTek 2” wheel spacers on my B26. 600+ hours and 7 years. Greatly helped on my hillside farm.
Tractors need spaced tires for their intended use.

4” spacers may be suspect. Over jealous tie down while trailering on pneumatic tire equipment puts high loads on axles too.

Respect analysis on why the axle broke but from what is still unknown. Improper outrigger support while digging? 4x4 on hard surfaces? Improper use of diff lock? Used equipment is always a guess.

Haven’t heard of another B26 axle breaking. Often used in rental because they can take abuse. Will be thinking about this.

One of the biggest questions that will not change is probably: How much was the tractor abused during its first 800 hours of life before the OP purchased it?

My gut says maybe the issue is independent of how the OP used the tractor.

I would have no problem putting 4 inch spacers on my B2910, honestly. It’s just the price of them that has held me back.

 

[pcproffitt]

I have BroTek 2” wheel spacers on my B26. 600+ hours and 7 years. Greatly helped on my hillside farm.
Tractors need spaced tires for their intended use.

4” spacers may be suspect. Over jealous tie down while trailering on pneumatic tire equipment puts high loads on axles too.

Respect analysis on why the axle broke but from what is still unknown. Improper outrigger support while digging? 4x4 on hard surfaces? Improper use of diff lock? Used equipment is always a guess.

Haven’t heard of another B26 axle breaking. Often used in rental because they can take abuse. Will be thinking about this.

Re: Improper outrigger support while digging? Guilty! Infrequent and generally minimal. Is it a best idea to ALWAYS use the stabilizers AND the bucket to support the tractor, rather than front and rear wheels, when using the backhoe? Obviously that's what the stabilizers are for. But, I didn't have the impression that using the backhoe without the stabilizers was a complete no-go situation.

 

[MapleLeafFarmer]

I have know this to happen before / not specifically with this model though.

Sometimes BH operators use rear stabilizers and front bucket properly while digging. But they choose to reposition back end either left or right by lowering the boom, lifting rear tires off the ground, then using swing to move back end over . I see it often when people digging stumps as bucket often jams out at the 12 o'clock position on the smaller machines so a reposition is desired.

When done gently and wheels placed on the ground no troubles. But if not done gently with tractor rear moving sideways with bottom of tires hitting ground at same time stopping the re-position the stress of sudden stop cams the wheel bottom in / top out. Pop happens. This is an abuse move when operator doesn't "place" the back end down after the swing stops.

Maybe old owner had this bad habit??

regardless with 1,000hrs. it is still a fantastic machine with lots of life left in it so fix has to be done. (ouch). Any guess what this would cost from a dealer?

 

[John D 2]

I have read on JD forums about 2025R having rear axle failures too.

I'm not saying it caused it, but there is one constant in the failures. . .

All the tractors had rear wheel spacers on them at the time of the failure.

 

[pcproffitt]

I have know this to happen before / not specifically with this model though.

Sometimes BH operators use rear stabilizers and front bucket properly while digging. But they choose to reposition back end either left or right by lowering the boom, lifting rear tires off the ground, then using swing to move back end over . I see it often when people digging stumps as bucket often jams out at the 12 o'clock position on the smaller machines so a reposition is desired.

When done gently and wheels placed on the ground no troubles. But if not done gently with tractor rear moving sideways with bottom of tires hitting ground at same time stopping the re-position the stress of sudden stop cams the wheel bottom in / top out. Pop happens. This is an abuse move when operator doesn't "place" the back end down after the swing stops.

Maybe old owner had this bad habit??

regardless with 1,000hrs. it is still a fantastic machine with lots of life left in it so fix has to be done. (ouch). Any guess what this would cost from a dealer?

I have no specifics on how the tractor was used before I purchased it. There are some indications is was NOT treated gently (broken plastics, bent boom lock lever, missing boom lock pin, broken brake linkage on one side. I also have no idea if the hydraulic fluid was ever changed. The original (to me) filters were much in need of replacement (which I did last year) including replacing all the hydraulic fluid and front wheel fluids.

I'm familiar with this repositioning dance using the backhoe. I had to do it to move the tractor (sans rear wheel) to a better position for the roll back truck to easily pick it up for transport to the dealer. Every time I've used that (mostly for digging stumps as noted) I've been really careful doing it. Most times I've had the stabilizers down while moving using the backhoe.

As for cost, I'm hoping to find out something by the end of this week. The axle itself lists for almost $800. Bearings and seals would add the better part of another $100. Replacement hydraulic fluid (UDT2) would be at least another $100. Labor on that would likely at least double that. Labor to remove the backhoe, loader, and subframe just to get to the transmission casing, that's the big ticket. I'm guessing $1000-$2000. So my wild guess is $3000-$4000 for one axle and $4000-$5000 for both axles (which I intend to do). I plan to have them check the brake discs and plates while the transmission end covers are off. And I have some other linkage issues I want them to check. So this is going to be an expensive trip to the dealer. The silver lining is that coming out of it the tractor will be in better shape than when I bought it. I'm looking for all the positives I can.

 

[MapleLeafFarmer]

I have no specifics on how the tractor was used before I purchased it. There are some indications is was NOT treated gently (broken plastics, bent boom lock lever, missing boom lock pin, broken brake linkage on one side. I also have no idea if the hydraulic fluid was ever changed. The original (to me) filters were much in need of replacement (which I did last year) including replacing all the hydraulic fluid and front wheel fluids.

I'm familiar with this repositioning dance using the backhoe. I had to do it to move the tractor (sans rear wheel) to a better position for the roll back truck to easily pick it up for transport to the dealer. Every time I've used that (mostly for digging stumps as noted) I've been really careful doing it. Most times I've had the stabilizers down while moving using the backhoe.

As for cost, I'm hoping to find out something by the end of this week. The axle itself lists for almost $800. Bearings and seals would add the better part of another $100. Replacement hydraulic fluid (UDT2) would be at least another $100. Labor on that would likely at least double that. Labor to remove the backhoe, loader, and subframe just to get to the transmission casing, that's the big ticket. I'm guessing $1000-$2000. So my wild guess is $3000-$4000 for one axle and $4000-$5000 for both axles (which I intend to do). I plan to have them check the brake discs and plates while the transmission end covers are off. And I have some other linkage issues I want them to check. So this is going to be an expensive trip to the dealer. The silver lining is that coming out of it the tractor will be in better shape than when I bought it. I'm looking for all the positives I can.

ouch on the cost... am I ever out of touch.

I too reposition rear with boom and like you take care doing it as I was one having to pay for stuff.

your machine is well worth it though. those 26tlb's are know to be real workhorses. Something I always wanted to own before I aged out.