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