M120 3 pt lift problems - lift light flashing fast, no interior lift controls

[rScotty]

(writing about) ........snip....
.........the control cables for the remote hydraulics. I REFUSE to pay $141+ for a control cable that is of a faulty design. Eight years ago, the same cable was $80.snip... The stranded cable within the sheath will be cold worked and then break in a short order of time. I now have custom cables made with a solid core wire for less than half of what Kubota wants for its branded parts. After going through 3 stock cables over the years, I have lost faith in Kubota's engineering skills.

On the M59, I had the auto-throttle cable break where it wrapped around the throttle drum. Just as you say, it was a fatigue failure due to bending. The break was sharp and straight across without stranding. It looked as if it had been cut with a knife and the broken cable ends showed the crystallization typical of fatigue. That was surprising; I'd expected the cable break to be one of the more common types of stranded cable failures that's just a part of the nature of cable controls. Things such as the strands stretching unevenly or not being soldered into the end properly.....like I said, we've all seen that sort of thing in cable controls. Or perhaps I'd find that dirt in the cable had caused it to break..... But the break I found was simply a cold work metal fatigue failure that happened within a clean well-lubricated rubber bellows. It was several inches away from the end of the cable, and no dirt was possible.

Then I got to thinking that maybe the cable movement required it to crimp somehow, but a little investigation showed that wasn't the case either. The engineering seems decent enough. The drum that the auto-throttle cable turns when the speed is set is a fairly large diameter smooth metal drum, easy to turn, and the drum contains a windup spring so that the cable is only required to pull on the connection; it never has to act as a pushing cable. Frankly I didn't see any immediately obvious reason for cable fatigue to happen where it did .

It was a puzzling cable break; I've never been satisfied that I got the reason for it figured out. Guess I kinda figured it to be a one-of-a-kind thing.

I wonder if we ought to start a separate thread on cables and see there's a manufacturing problem we can cure.
thanks,
rScotty

 

[MHarryE]

Won't have time to look in my WSM until I get out of the field tonight. Not sure how your Mqe0X differs from my M135GX. My light frequently flashes at start up until I cycle the control a little. It's due to valve leakage, even slight, and the system needs to determine top of lift sgain. Your problem, however, is now more severe. I'll check out trouble shooting.

 

[Texas Fella]

As far as the 3 pt problem, goes, here is an idea. On the M120's, there is a position sensor on the 3 point. If it gets "confused" then the internal controls of the 3 point shut off until the issue is correct. An example is as follows: If you shut your tractor off with the 3 point in the lower position, and then (with the key in the off position) move the controls lever for the 3 point into the upper most position, then start the tractor, the ECU sees the controller in the "up" position, but the arms are in the "down" position. This will lead to a flashing light and loss of internal (inside cab) control of the 3 point. In most cases, if you simply move the lever to the correct position (lowered) or just move the lever back and forth slowly once the ECU "sees" the control lever match with the position it will usually correct itself. In some extreme cases, you may need to lower the 3 point manually (using the fender mounted buttons), lower the control lever in the cab, and shut the unit down and restart. If you have to do that, it is very rear and usually hints towards another issue. If this does not help, I would start with checking/replacing the 3 point position sensor as it is usually the issue in this situation. I do want to stress that I would not just replace the senor without trying the above mentioned items. Even though the sensor is the most common failed item, the failure rate on those is still very low, I would have to see you waste money. As always, just my two cents.

 

[MessickFarmEqu]

After a customer told me his new Kubota was useless for 30 minutes every time it went into exhaust regen, I have no plans for anything new in off road diesel. I hate the DEF and regen in my new Ford but the clean tailpipe is a bonus.

Guy does not understand how a regen works. Unless you bypass the automatic process several times and are forced to a parked regen the process happens while your working.

I 2nd the position sensor on the 3pt, great explanation.

 

[MHarryE]

Guy does not understand how a regen works. Unless you bypass the automatic process several times and are forced to a parked regen the process happens while your working. I 2nd the position sensor on the 3pt, great explanation.

I'm with you on the person who talked about a regen being a stop everything event. I now have 700 hours on my M135GX and the only way I know it has had several regens is by the flashing light that says its in regen mode and the percent of DPF filled dropping back to zero. Where do these regen horror stories originate? Do the smaller tractors have a different system that causes problems? I have 3 neighbor's with DPF equipped Kubotas and none have had to do anything more than drive and let the system do its thing when needed.

 

[MessickFarmEqu]

There is nothing different between your M135 and any other tractors.

 

[slowzuki]

RE the original issue, there is extensive info in the workshop manual to diagnose the hitch problems both using the computer or manually checking voltages/resistances.

It also has a badly translated description of the things that trigger the hitch lock (slow flashing light) and they seem to be needlessly complicated but explains why it locks in so many situations.

 

[ozzie tractor]

thank goodness we go some sensible info on this subject.
ok lets start at the 3pl. yes as mentioned if the 3pl sector is in a different position to the 3pl arms it will SLOW flash. as mentioned move the sector up and down or hit the quick lift buttons to fix it. they do this basically every time you start up due to a tiny bit of creep over night. if you use your guard buttons, this will cause it too. when using the guard buttons, you can "top" the 3pl out. the 3pl if calibrated correctly cannot normally lift this high, so moving the sector will not ever get to a position where the 3pl and sector are at the same position. you have to use the guard buttons to lower the 3pl a bit and then move the sector up and down to line the two up.
the light flashing quickly indicates a fault. as in a FAULT CODE. you really should have called the dealer with this. his first question would be describe the flashing. is ut fast or slow or both. but we can bypass all this and ill have a red hot guess that the wires that are hanging down behind the seat that go to the RH arm rest are damaged. it about 4000 times more common than a sensor issue. its caused by pilling chains, pins, lunch boxes and rags on to of the wires and as the seat rides up and down it stretches the bejezuz out of them and they fail. so there you go. no pesky expensive spare parts required. id also suggest that swapnostics is the lowest form of diagnosis and will not find a broken wire, which on a kubota is 95% of the time the problem. you need a multi meter and a wiring diagram and the knowledge on how to use both. also the part of the wsm that covers 3pl fault codes and how to put the 3pl in diagnostic mode if very handy and takes the quess work out of it. either that or call the dealer tech out to have a look. if hes any good it should take about 2hrs max.

 

[ozzie tractor]

next onto mgx dpf's
the earlier dpf was set to inhibit burn which required the operator to press the auto burn button when the ORANGE light came on the dash. if you didnt, eventully you got a red light and a fault code. when it gets this far, you must do a parked burn. if you pressed the button when you should have, you could keep working and it would have done a burn while you worked. the only thing it required was at least 1500rpm or more. so its hardly useless.
now the later ones, because reading the owners manual and pressing a button every 40 or so hrs was all to confussing and hard to do, are set at press to inhibit. so the light comes on and they automatically do a burn, but you can press the inhibit switch if you in a high fire risk location such as a hay shed etc. now its the same again, 1500+rpm and you keep working. if you keep pressing inhibit, it makes you do a park burn. if you keep going long enough, it will derate and throw some big angry fault codes. you then have to get a tech to plug in to it and do a "forced burn" while he data logs the exhaust temps, trying to avoid burning the dpf up.
as a side note, try to let the machine finish a burn before you shut it down. if you interupt a burn, the next time you start it, it will do a super slow, long burn. it cant tell where the burn was up to so it proceeds very slowly. also machine that work hard burn of less.

 

[ozzie tractor]

lastly (sorry about raving) m135x vs mgx is a lot different. diagnostics on an mgx are done though the lcd on the left of the steering wheel and has a totally different procedure. the m135x is done via a series of tests using the gear indicator to confirm each step is correct. mx leterature isnt much use for an mgx.