Kubota M59 pops out of gear when going downhill?

[lwm]

Hi all,

I've had a M59 pop out of gear on me twice. Once in high, once in medium. Both times going down a hill.

After the first time I'm very careful about being in gear, when I shift I check the lever and make sure it is in
place and I go forwards and backwards to see if it pops out.
I've got some sketchy work in front of me, steep hillsides, need to move 20 yards of dirt. I can't have it pop
out again, I don't have the runway to stop it. So I'm looking for insight, is this an M59 thing? I've got a B21
and it has a much more secure shift pattern, it's never popped out.

Thanks for any insight.

--lm

 

[Grandad4]

Well, lm, I tried to give you some useful advice about re-posting your issue here, but evidently all the M59 owners are on a long weekend break. I don't know enough about the shift setup on an M59 to say anything very useful, but wish you success in resolving the problem.

 

[lwm]

The shift setup is a lever that goes L N M N H where N is neutral. It is in a straight line like a position control valve lever. It has detents that are supposed to hold the lever in place and I'm guessing that's what is failing. My shade tree mechanic says detents are either internal or external and mine seem to be internal. He thinks that they are just not holding and that's my problem. If he's right then I've got a ginormous bill in front of me because you have to tear the tractor apart to get at them.

I'll call the Kubota service people on Monday and see what they say.

Thanks for nudging me over here, I didn't know this part existed (not much of a forum guy, I'm usually on the tractors).

 

[rbargeron]

The shift setup is a lever that goes L N M N H where N is neutral. It is in a straight line like a position control valve lever. It has detents that are supposed to hold the lever in place and I'm guessing that's what is failing......

I would suggest a careful inspection and lubrication of the shift lever linkage. There's more to it than on some models. It starts with a long rod that runs from the hand lever thru sleeves and through the top of the trans where it connects to the internal shift fork. The rod continues thru and connects to more switch linkages on the other side.

There are several places where a tight sleeve, dragging pivot, or slightly bent rod could influence the shifting. The detents are inside the trans and not likely to wear or stick. But all that external linkage could be creating some resistance that keeps the shift fork ball from fully dropping into the intended detent groove.

If the whole external linkage is free to slide, turn, and move easily it should stay in gear once its in.

Edit: My neighbor's tractor had very weak detents and would come out of Hi or Lo range into neutral unexpectedly. We fixed it by adding a notched plate at the shifter slot that positively holds it in each position - shifting requires slightly springing the lever sideways to get out of the notch its in. Would something like that be possible on your rig? Good luck, Dick B

 

[lwm]

Dick, that's some good advice on both points. I'll take things apart and look at the linkages. I tend to think the dentents are fine, this tractor has 470 hours on it, seems crazy they'd go bad that fast.

I think I could do the notched plate but I'm not sure my lever moved when it popped out, it's only happened twice and I was sort of butt clenching at the time, didn't think to look.

 

[rbargeron]

The internal pin/fork/detent mechanism is a positive assembly. It's either locked together with the lever or disconnected and flopping. To come out of gear the lever has to move too unless something is broken or missing.

Searching TBN brought up this discussion from 15 years ago about M6800s coming out of gear. Kubota did help out - supplying new parts. Part of the solution was machining detent grooves deeper.

Here's hoping that smoothing up the linkage does the trick. Putting on a notched shifter plate might add a "confidence factor" to support the work you have coming up. Dick B

 

[rScotty]

Hi all,

I've had a M59 pop out of gear on me twice. Once in high, once in medium. Both times going down a hill.

After the first time I'm very careful about being in gear, when I shift I check the lever and make sure it is in
place and I go forwards and backwards to see if it pops out.
I've got some sketchy work in front of me, steep hillsides, need to move 20 yards of dirt. I can't have it pop
out again, I don't have the runway to stop it. So I'm looking for insight, is this an M59 thing? I've got a B21
and it has a much more secure shift pattern, it's never popped out.

Thanks for any insight.

--lm

Hello lm, kicking out of gear is not a problem that I've heard of with the M59. In fact, the complaint is more often that the shifter on the M59 is difficult to move between ranges - possibly because the shifter detent mechanism is overly conservative. I know mine sure is hard to shift between ranges and all the others I've driven are too. But I can see what you mean about working on hillsides.....I hadn't thought about it, but when working on a slope I also depend on transmission braking to stay in control. So much so that I rarely use the brakes. And I never, ever shift ranges when moving or on a slope; that would be just asking for trouble. Probably most of us work the same way.

Back when the M59 first came out, Charles started a thread so that owners of this new species of Kubota could share thoughts. It finally went to 44 pages and is still going - although slowly now that M59s are more common. You might want to search on: M59 Discussion Thread and see if anyone has mentioned kicking out of gear. The thread is pretty good reading overall. Several of us live in mountainous country and one of the things that got us onto M59s is the slope stability.

I have had my M59 kick out of gear - but only once in 9 years. I remember it distinctly because it just happened last weekend. Here's what happened: I had been moving dirt on flat ground and stopped to shift from M into H range.....after the typical wrestling session with the lever I stepped on the go pedal just at the same instant that it flashed on my consciousness that the lever didn't feel like it had moved the right amount. We hadn't even started forward - the M59 was just sort of gathering itself - when there as a slight "pop" sound and all motion stopped. I glanced down, saw that the lever wasn't quite home in H and that the reason might have been because my leather glove had fallen against the back of the shifter lever. Anyway, after stowing the glove and shifting the lever properly into high we carried on. Nothing seemed damaged. So the only time it has happened to me I think it was operator error, no harm and no foul. My feeling is that one was on me and not on the tractor. And I feel good that it happened when shifting into H, not into Med. or Low. Because of the way the range shifter works I'm better at pushing it into L or M than pulling it into H. Frankly I'm kinda sloppy about shifting into High, maybe because that's the traveling gear rather than a working gear.

The key thing I take away from that is the tractor never really started to move before it kicked out of gear. And it reinforced that I'll never even be tempted to shift ranges while working on a slope. Now I will say that it it ever happens that it kicks out of gear after I've been working in a range for awhile then that would be a completely different situation. In that case I would be very concerned. At the least I'd be worried enough to take a serious look at the shifter mechanism. But so far I haven't seen or heard of that happening.

Please let us know how it turns out,
rScotty

 

[Stonehaller]

There are several places where a tight sleeve, dragging pivot, or slightly bent rod could influence the shifting. The detents are inside the trans and not likely to wear or stick. But all that external linkage could be creating some resistance that keeps the shift fork ball from fully dropping into the intended detent groove.

Good point. You could be feeling friction or binding in the linkage and think it is in the detent when it is not.