M59 Breakdown and Repair

[rScotty]

I guess it had to happen. After six years of working something finally broke on our M59. This machine is used for a lot of short chore work and has about 600 total hours. These tend to be hard hours but not high RPM hours. We don't idle much, tending to run with the Stall-Gard feature activated but with the Low/High auto shift feature not engaged. This combination works the auto-throttle pretty much constantly.

So I was pushing a load of flood debris - rock and dirt - when the HS foot pedal suddenly felt different and the engine dropped to an idle. Investigation showed that the wire cable running from the engine governor to the auto-throttle lever had broken. Actually I was glad to see that. My fear was that it was going to be something in the transmission or the magical software/electronic controls. A broken cable is something I can deal with....it being a typical control cable about like a motorcycle throttle cable or bicycle gear shift cable.
Luckily - or due to good design - the M-59 auto-throttle cable runs in parallel with the hand throttle cable so the tractor continued to work in manual throttle mode until the part arrived. Not a whole lot of difference really, and none at all as a backhoe.

I called Messick's part dept. and the pre-made cable came UPS about 3 days later. It has a different plating on the metal parts than the original, but otherwise it's the same high quality part. Sporting the proper type of multiple strand cable for a flex application, regular even crimps, good rubber - not vinyl - in the dust protection bellows, wire connection looks right, no extraneous solder creeping up the wire strands....all things that this old mechanic looks for in a pre-made flex cable. Roughly $30 plus postage. Postage was high, so I took the opportunity to buy a couple other cables just in case.

Replacing and readjusting the new cable should have been a one hour job but took twice that long because the cable routing is so difficult to access. Major POA, actually. Other than access, the installation was straightforward for anyone having tiny hands equipped with double jointed steel fingers. And possessing U-joints in place of the more common type of wrist, elbows, and shoulders.

I wanted to get this info out there. We haven't had many posts about Kubota repairs and even less on the M59. This wasn't a case of dirt or adjustment or lack of lube, overuse, or any of the traditional causes of preventable failures. In fact this cable is sealed against dirt. This cable is simply a stranded wire that has to bend to do it's job and it gets to bend a certain number of times before breaking. My guess is it simply reached it's design life and parted. It's working normally now.
rScotty

 

[LD1]

Nice detailed write-up.

Do you think that 600hrs of use is acceptable design life for that part?

I know you have used it for 6 years, but a contractor (that the machine is designed for) might put that on in a year.

 

[rScotty]

Nice detailed write-up.

Do you think that 600hrs of use is acceptable design life for that part?

I know you have used it for 6 years, but a contractor (that the machine is designed for) might put that on in a year.

Thanks for the compliment. I don't think it's related to hours but to useage. I do a lot of slow speed loader work over broken ground with the hand throttle set to idle. So my auto-throttle is constantly adjusting the throttle to the load. Each time it does so it flexes the cable around a drum. The lower the hand throttle is set, the more the auto-throttle has to move the cable. In my case it goes all the way from idle to full throttle and probably does that several times a minute. An operator who normally sets his hand throttle higher than idle..... or who does more backhoe work would rarely see his auto-throttle function working at all. For that person the service life of that part would be in the thousands of hours instead of hundreds.
I'm not above re-designing a part if it needs it. This seems like a decent design as near as I can tell. Not sure how I would design it differently...
rScotty

 

[FatTire]

Roughly $30 plus postage. Postage was high, so I took the opportunity to buy a couple other cables just in case.

Good thinking. Its not just the shipping, but time to find the P/N's and place the order. Not to mention the down-time.

 

[mmorisoli]

By the way most motorcycle shops sell a cute little adapter that slides over the cable end and clamps down with a nice rubber seal and special cable lube that you can use to lube these type of cables. When you squirt in the lube it will blast out at the other end making sure the entire length is lubed and cleaned.

I did that on my L3940 at 100 hours and again at 400 hours and was surprised how much smother all of the cable based levers and peddles felt.

 

[rScotty]

By the way most motorcycle shops sell a cute little adapter that slides over the cable end and clamps down with a nice rubber seal and special cable lube that you can use to lube these type of cables. When you squirt in the lube it will blast out at the other end making sure the entire length is lubed and cleaned.

I did that on my L3940 at 100 hours and again at 400 hours and was surprised how much smother all of the cable based levers and peddles felt.

I don't see any downside to that. I've used a similar gadget since the 60s on my motorcycles. It won't work in this application because the end of the cable exposed to dirt is completely covered by a crimped on rubber bellows, leaving nowhere for the blast to exit. Surprisingly, the break in the cable happened inside this bellows.

I took the cable out of the sheath and examined the broken end. Unlike most cable failures I've seen, this one is not a normal tension failure common on motorcycles where each intact strand stretches a tiny bit more as the strand next to it breakes. This break is straight across all the strands - almost like it was cut there with a knife. The point of failure is exactly at the maximum bend.

The inner stranded wire was well lubed - looks like some sort of oily graphite lube - and no dirt in there at all. It was running freely when it broke.
After fixing it I've begun to run the tractor at a higher idle - about 1400 rpm instead of 900 for loader work and 1500 for hoe - doing that reduces the reps on the auto throttle.
rScotty

 

[lhansman]

Thanks for posting this rScotty. I will have to check and see if I have the same issue on the L45 as I am approaching 650 hours now.

Did you see my PM response to your earlier inquiry via PM to me?

Lauren

 

[rScotty]

Lauren, I don't know if that cable is traditionally checkable....certainly you cannot see, lube, or clean it. But I think there is a way we can check it. The most highly stressed part of that cable is what broke on mine. The place it is likely to breakcan only be seen from UNDERNEATH the tractor approx. directly under and and 12" behind the HST foot control. When you actuate the HST foot control to send instructions to the transmission as to how fast and in what direction you want to go then this cable also moves and tells governor on the right side of the motor to rev up for the load. It's the auto-throttle cable. So when you call for more HST fluid with your foot, the cable revs up the motor at the same time. I like this feature of automatically revving to meet the load. It's one of the reasons I chose the M59 over the JD110.
So...down there under the tractor where things are dirty that stranded end of the cable is enclosed in a molded non-removeable rubber bellows A guy can't see the cable and there isn't any way to get into it to clean or lube it. Not that it needs that kind of attention; mine was clean and lubed. But luckily for preventive maintenance, the bellows is a nice soft rubber which you can squish between your fingers and so feel if any of the strands of the cable have parted and are sticking up. It's strictly a "how often the auto-throttle it is used" type of failure. I use mine a lot, and often go back and forth a few feet under load all day long when doing landscaping.

Oh..yes, I did see your PM. Great info. For anyone following along here, in that PM Lauren and I were discussing cost of cabs for the L45/L48/M59....as I was deciding what to do. The upshot is that a cab for the M59 turned out to be so expensive that I found I could buy a fairly new industrial TBL with a cab, heater, AC and all the accessories for about the same price as putting a cab on the M59 would cost. So that's what I did.

Maybe we should start a thread on Kubota Cabs? Having owned half a dozen or more TLBs now for over 40 years I think my opinion has the weight of experience. And I think the M59 could be miles ahead of the competition - even compared to commercial backhoes like the Deeres, Cases, and Cats. It is simply the best of that type I've ever used - mostly because of the hydraulic controls and HST transmission. But the M59 has three things that hold it back: Not having a factory cab is the real killer, also there is not enough foot room when reversing the seat, and no vertical exhaust. The latter two can be fixed easy enough, but the lack of a factory cab limits their market.

This is so obvious....and so easily remedied.....that it can only be that they deliberately want to stay away from the commercial TLB market. I wonder why? They already build factory cabs for some of their other machines. My dealer says there are no plans to add a cab for the M59.
rScotty

 

[capt_met]

I'm with you on the cab thread. 3 seemingly simple fixes to make it a legit commercial machine. I will be doing the same thing later this year and purchasing a used 310-580 sized machine.

 

[rScotty]

I'm with you on the cab thread. 3 seemingly simple fixes to make it a legit commercial machine. I will be doing the same thing later this year and purchasing a used 310-580 sized machine.

Your message got me to thinking....and the thought that kept coming up was how interesting it is that the three things that the M59 needs changed are all related to operator comfort - there's nothing in there about how the machine does it's work. Not sure what it means, but there it is... .

Having both machines and doing real dirt moving all day most days I can begin to make some comparisons.

I'm surprised to find that for simple one or two hour jobs and especially for jobs where I am on and off the machine a lot I definitely prefer the Kubota. I'd have thought the 310 would get the bulk of the work time but that hasn't happened. Of course the weathers been good, too.

The M59 is nimble, quick easier on/off and has a little more rough country sideslope stabilty than the JD310SG. Great visibility too. The M59 is as handy as a pocketknife.
However, if I'm going to be on the machine for longer than a few hours - or the weather is nasty - or if I need to road it for a few miles - then the nod goes to the JD310. Working the M59 all day is way more tiring than working the JD310.

Both machines have 4wd; the 310 has a much tighter turning radius than the M59; that sure surprised me. The JD310 also has higher ground clearance and far superior parking brakes. And the JD310 loader bucket is bigger but harder to see around. Also, the JD bucket doesn't tilt back as far as the M59 bucket so it doesn't heap as well. The upshot is that usable bucket capacity isn't all that different. The 310 has lots more breakout muscle. Especially compared to the M59 which suffers on breakout. I often have to back up and lift it twice to get the bucket free - although that is so easy with the foot operated HST that it's kinda mindless....just part of the motion.... Once broken out and full, either machine will handle a bucket full of any material without even noticing.

Both machines have decent hydraulic control sensitivity. The JD310's power shift is nicer than their old floor stick, but doesn't hold a candle to the Kubotas 6-speed HST tranny.
rScotty

 

[lhansman]

Hi rScotty

I too thought about purchasing a used full size machine to get a cab before I got the L45 but in the end I decided I didn't want to deal with trailing a large machine as I do a lot of side jobs in the summer so my L45 moves around a lot. I almost purchased a used 2008 M59 with 500 hours on it which already had the Laurin cab on it as well as front remotes and the backhoe thumb. Unfortunately I read a few posts about guys having expensive hydraulic pump problems with early M59's and that made me nervous so I opted for the L45 instead.

I am glad you have a machine with a cab rScotty. Years ago I was in logging and used to work in the northern Ontario bush in temperatures up to -40 degrees but I can no longer take the cold. There is nothing like pushing snow in a raging blizzard in a T-shirt!

Thanks for the tips on the cable - I will check mine out this weekend. I use auto-throttle all the time so there may be some issues with mine too. In fact I use it so much that during the fitting of my snow blower last fall the dealer kicked the switch out of the Auto-throttle detend and it took me a few minutes to figure out why the engine would not rev when I stepped on the HST pedal.

Regards,

Lauren

 

[rScotty]

Darn....I must have missed those M59 posts. And I have one of those early M59s!@ .Although maybe that's a good thing as it has turned out OK. A hydraulic pump problem is a new one on me. If you still have links to the posts please send them along.

I had heard that many of the early M59s sat on dealers floors longer than expected. My dealer said the M59 made its debut at the annual Kubota dealer's convention where a special deal was offered to dealers placing orders. Since times were good, dealers ordered lots. Then just a few months after delivery came the famouns 2008 downturn in US economics......So the machines just sat.

Ours is one of that early lot, but I haven't heard about a pump problem. So far if I had to choose between the 310 and M59.... the nod would go to the M59 for usability and to the 310 for operator comfort.
rScotty

 

[MessickFarmEqu]

I don't doubt some day there maybe a cab on the M59. Its been a long requested feature and Kubota seems intent on strengthening its position with commercial operators.

 

[SPYDERLK]

I guess it had to happen. After six years of working something finally broke on our M59. This machine is used for a lot of short chore work and has about 600 total hours. These tend to be hard hours but not high RPM hours. We don't idle much, tending to run with the Stall-Gard feature activated but with the Low/High auto shift feature not engaged. This combination works the auto-throttle pretty much constantly.

So I was pushing a load of flood debris - rock and dirt - when the HS foot pedal suddenly felt different and the engine dropped to an idle. Investigation showed that the wire cable running from the engine governor to the auto-throttle lever had broken. Actually I was glad to see that. My fear was that it was going to be something in the transmission or the magical software/electronic controls. A broken cable is something I can deal with....it being a typical control cable about like a motorcycle throttle cable or bicycle gear shift cable.
Luckily - or due to good design - the M-59 auto-throttle cable runs in parallel with the hand throttle cable so the tractor continued to work in manual throttle mode until the part arrived. Not a whole lot of difference really, and none at all as a backhoe.

I called Messick's part dept. and the pre-made cable came UPS about 3 days later. It has a different plating on the metal parts than the original, but otherwise it's the same high quality part. Sporting the proper type of multiple strand cable for a flex application, regular even crimps, good rubber - not vinyl - in the dust protection bellows, wire connection looks right, no extraneous solder creeping up the wire strands....all things that this old mechanic looks for in a pre-made flex cable. Roughly $30 plus postage. Postage was high, so I took the opportunity to buy a couple other cables just in case.

Replacing and readjusting the new cable should have been a one hour job but took twice that long because the cable routing is so difficult to access. Major POA, actually. Other than access, the installation was straightforward for anyone having tiny hands equipped with double jointed steel fingers. And possessing U-joints in place of the more common type of wrist, elbows, and shoulders.

I wanted to get this info out there. We haven't had many posts about Kubota repairs and even less on the M59. This wasn't a case of dirt or adjustment or lack of lube, overuse, or any of the traditional causes of preventable failures. In fact this cable is sealed against dirt. This cable is simply a stranded wire that has to bend to do it's job and it gets to bend a certain number of times before breaking. My guess is it simply reached it's design life and parted. It's working normally now.
rScotty

An obvious design problem. If youre good with it fine, but no correctly designed application should fail in 600 hrs doing the normal job its designed for. You are a highly desired customer blaming yourself. Im sure Kub loves you.
larry

 

[rScotty]

An obvious design problem. If youre good with it fine, but no correctly designed application should fail in 600 hrs doing the normal job its designed for. You are a highly desired customer blaming yourself. Im sure Kub loves you.
larry

Interesting comment, Larry. I'm sure Kub does so far.....but not so sure that they will if they read this. Having designed equipment myself for 40 years I am well aware that no designer can anticipate all eventualities and of course we all do make mistakes. So I'm inclined to be lenient to start

To my way of thinking, the big mistake was in making the control cable replacement so difficult to access. It looks as though the cable was installed BEFORE the cab floor was put on. Of course the order of assembly is a manufacturing engineer's decision and although the design engineer can over-ride that, doing so means that the engineer would somehow be aware of what manufacturing is up to........not always an easy thing to find out.

And keeping your alleged "Kubota Love" intact is going to depend a lot on how they respond when they recognize this or any items that need to be improved. I'd say it's not about the mistakes, but about how ready they are to fix those mistakes.
So far their response record at that is spotty.

Getting more technical for a minute, my initial thought was that 600 hours is a reasonable lifetime for a cable end moving through a significant bending angle that often. Darn, if we knew the additional tensional stress it gets from pulling on the governor we could evaluate this design in short order because control cable technology is pretty mature now that it has been used for over 50 years in everything from airplanes to bicycles. On reps alone though we can at least do something...lets see...that would be about six to ten times a minute and 60 to an hour....Well that's about a quarter million cycles and yes - now I find I do agree with you; a quarter million cycles does seem too low a number. Unless the governor's tensional stress is lots more than I thought, I'd have expected to get a million cycles at least. A million being a sort of magic number for bending reps in manufacturing.
Although a sample size of one doesn't mean much - except to make me feel a little better about the replacement cable because the life was so short that it's possible I just got statistically unlucky with the first one. To compensate I'll buy a lottery ticket next time I go to town. But for real info we'll have to see if other owners have the same problem. That might not take long. It wouldn't surprise me to find Kubota using the same control cable technology across the board.

Like every mechanic that ever was, I never fix anything without spending some time thinking about how I would have designed it myself. In this case I'm not sure. That looks like just about everything that can be done to a control cable that I know about. It is absolutely sealed, multistranded thin wire, permanently lubed, and the end is fastened mechanically rather than soldered. All the stress-relieving shapes are in the right places, the choice of materials looks good, the ends are compressed well. If it breaks again I'll put some real thought into mounting the end in a bearing or changing over to an electrically driven servo system. Unfortunately the required distance is just too far for using a solid control rod.
rScotty

 

[rScotty]

I don't doubt some day there maybe a cab on the M59. Its been a long requested feature and Kubota seems intent on strengthening its position with commercial operators.

I disagree. I contacted several dealers last fall and again this spring and had them ask Kubota that very question: Were there any plans for a cab for the M59?. I did what I could to check that the my question got to the proper Kubota representatives. My question included an an offer to pay any reasonable price for a prototype cab, or to help to adapt an existing Kubota ag tractor cab, and even to help Kubota with their design. I've a lifetime experience in engineering design and that was also included.

The one reply I got back was from the West Coast and said that after checking back with the factory they had no plans to offer an M59 cab and also had no development program to design such a cab.

BTW, I also see no evidence at all to support your contention that Kubota is "intent on strengthening their position with commercial operators". Nor do any local dealers support your viewpoint. What are you basing your opinions on?

Our JD310 with an air-conditioned cab is nice, but the technology is older. As I've said before, I actually prefer many features of the M59 Kubota and use it by preference when I can.....that's surprising since the JD is at least 2x the cost.
Scotty

 

[SPYDERLK]

Interesting comment, Larry. I'm sure Kub does so far.....but not so sure that they will if they read this. Having designed equipment myself for 40 years I am well aware that no designer can anticipate all eventualities and of course we all do make mistakes. So I'm inclined to be lenient to start

To my way of thinking, the big mistake was in making the control cable replacement so difficult to access. It looks as though the cable was installed BEFORE the cab floor was put on. Of course the order of assembly is a manufacturing engineer's decision and although the design engineer can over-ride that, doing so means that the engineer would somehow be aware of what manufacturing is up to........not always an easy thing to find out.

And keeping your alleged "Kubota Love" intact is going to depend a lot on how they respond when they recognize this or any items that need to be improved. I'd say it's not about the mistakes, but about how ready they are to fix those mistakes.
So far their response record at that is spotty.

Getting more technical for a minute, my initial thought was that 600 hours is a reasonable lifetime for a cable end moving through a significant bending angle that often. Darn, if we knew the additional tensional stress it gets from pulling on the governor we could evaluate this design in short order because control cable technology is pretty mature now that it has been used for over 50 years in everything from airplanes to bicycles. On reps alone though we can at least do something...lets see...that would be about six to ten times a minute and 60 to an hour....Well that's about a quarter million cycles and yes - now I find I do agree with you; a quarter million cycles does seem too low a number. Unless the governor's tensional stress is lots more than I thought, I'd have expected to get a million cycles at least. A million being a sort of magic number for bending reps in manufacturing.
Although a sample size of one doesn't mean much - except to make me feel a little better about the replacement cable because the life was so short that it's possible I just got statistically unlucky with the first one. To compensate I'll buy a lottery ticket next time I go to town. But for real info we'll have to see if other owners have the same problem. That might not take long. It wouldn't surprise me to find Kubota using the same control cable technology across the board.

Like every mechanic that ever was, I never fix anything without spending some time thinking about how I would have designed it myself. In this case I'm not sure. That looks like just about everything that can be done to a control cable that I know about. It is absolutely sealed, multistranded thin wire, permanently lubed, and the end is fastened mechanically rather than soldered. All the stress-relieving shapes are in the right places, the choice of materials looks good, the ends are compressed well. If it breaks again I'll put some real thought into mounting the end in a bearing or changing over to an electrically driven servo system. Unfortunately the required distance is just too far for using a solid control rod.
rScotty

Good analysis. Where exactly did the cable fail. Did it break clean or fray? Is the design complimentary to multi strand cable such that only pull forces are called for, or is it push pull?
larry

 

[rScotty]

Good analysis. Where exactly did the cable fail. Did it break clean or fray? Is the design complimentary to multi strand cable such that only pull forces are called for, or is it push pull?
larry

Pics: disassembled after end of cable, after end of cable before disassembly, governor end of cable.

Thanks. Yes, you have a good question. This is a multistrand cable used only for pulling forces. Return forces are supplied by springs at the other end within the governor. The unbroken end pulls on a drum to rotate the governor. Connection there is around a about a 4" diameter drum that is large enough so that bending is small.

The after end that broke is within the rubber bellows and it broke cleanly inside that bellows about .01" from where it is compressed into the bronze aft ring eyelet. That's the eyelet that surrounds a pin on the end of a lever leading into the transmission. The broken end did fray, but because the breaks are all on the same perpendicular plane to the cable it looks to me like the cable frayed as a result of the successive parting of the strands at the high stress location. see pics.

When I took a look today I noticed signs of galling on the inside of the bronze ring eyelet. That would seem to indicate that the eyelet didn't rotate freely on it's pin and of course that would increase the bending of the cable wire. Looks like that may be the cause. That area is accessible for lubrication - with some difficulty, but accessible. If it had gotten a few drops of oil from time to time it probably would have lasted longer. Now that I'm looking at the galling of the eyelet it makes me think that's all it needed.

Thanks again. Great question, Larry! It might have led us to a cure - at the least improved things.
rScotty

 

[SPYDERLK]

View attachment 373700View attachment 373702View attachment 373703

Pics: disassembled after end of cable, after end of cable before disassembly, governor end of cable.

This is a multistrand cable used only for pulling forces. Return forces are supplied by springs at the other end within the governor. The unbroken end pulls on a drum to rotate the governor. Connection there is around a about a 4" diameter drum that is large enough so that bending is small.

The after end that broke is within the rubber bellows and it broke cleanly inside that bellows about .01" from where it is compressed into the bronze aft ring eyelet. That's the eyelet that surrounds a pin on the end of a lever leading into the transmission. The broken end did fray, but because the breaks are all on the same perpendicular plane to the cable it looks to me like the cable frayed as a result of the successive parting of the strands at the high stress location. see pics.

When I took a look today I noticed signs of galling on the inside of the bronze ring eyelet. That would seem to indicate that the eyelet didn't rotate freely on it's pin and of course that would increase the bending of the cable wire. Looks like that may be the cause. That area is accessible for lubrication - with some difficulty, but accessible. If it had gotten a few drops of oil from time to time it probably would have lasted longer. Now that I'm looking at the galling of the eyelet it makes me think that's all it needed.

Thanks again. Great question, Larry! It might have led us to a cure - at the least improved things.
rScotty

I think youre right. Also it would be good to know if the lever CAN push, or only pull and relax.:confused3: .... As for alleviating the issue in present form, the best lube I know is Militec. Its a surface modifying lubricant that seems to impregnate the surface and have lasting effect. An oil, or put a couple drops into light grease. To ruggedize the stress riser area next to the crimp consider solvent clean and apply a drop of Loctite Wicking compound. This should lock the strands together for a short distance out and ease the stiffness transition.
larry

 

[MessickFarmEqu]

The one reply I got back was from the West Coast and said that after checking back with the factory they had no plans to offer an M59 cab and also had no development program to design such a cab.

maybe some divisional differences. Cabs are a bigger deal for us in the North East than any other division. The opinion about its necessity may vary. If you are so interested, i do believe there are aftermarket options. We've done them on the L45, but not the M59.