GR2120 stall on hill

[JanB]

Recently I had an engine stall while mowing which resulted in a runaway situation going BACKWARDS down a steep hill. Attempting to turn every so slightly to go across the hill resulted in a roll over. Twice... before being pinned under the GR2120. Luckily I am alinve to write this RFI. I have heard from a dealer that stalls such as these have occurred and that the failure of the hydrastat system allowed a free spooling condition and thus "the runaway tractor."

I am searching for other occurrences of this situation. PLEASE RESPOND WITH ACTUAL ACCOUNTS ONLY. The last thing I want to read are: "it might be this..." or "it might be that". Forums and users who do this really waste valuable research time. So please... ACTUAL ACCOUNT details only.

So far the dealer has yet to come and pickup the tractor for repair. This concerns me. but what concerns me more is that there seems to be a known anomoly in the GR2120 family of tractors that may have even resulted in deaths. My situation was very close.

My goal is to find out what went wrong and whether it might happen again. Going to a BX with ROPS is certainly a desired option if Kubota will credit me the cost of this mower (only 64 hours).

Respectfully,
Jan B

 

[North Idaho Wolfman]

What happend to using the brake?

 

[sitric]

New member comes on, and makes demands of what is posted, and insults a mod. That is always a good way to start.

 

[JanB]

New member comes on, and makes demands of what is posted, and insults a mod. That is always a good way to start.

Interesting... would YOU be insulted if someone stated the obvious?

Not what I expected here... nor even close to what I asked for. I'll let this ride for a week and see if I get any real answers... then all y'all are welcome to continue doing whatever you do. As yes... I was surprised he was listed as a moderator... far from professional. My comments were emotional. The tractor almost killed me. Get it... ALMOST.

 

[lmichael]

Honestly looks to me you came on here asking questions you should be asking an attorney. One has to wonder on a GR2120 about the whole scenario. It's a hydro trans. Similar (not the same as my 2160). If power goes away it does not free wheel. Hydros don't have a "neutral" as in a regular gear box. Were the limits of the machine exceeded we don't know. Only you really know the answers to all this and my guess is an attorney is where you need to be

 

[NCL4701]

Interesting... would YOU be insulted if someone stated the obvious?

No.

If I went through a traumatic situation where I almost killed myself (and I have) I would want to analyze and have some feedback on how to avoid a similar result that might actually kill or seriously injure me in the future even if that feedback included some question of operator error being a component of the result, albeit possibly not the proximate cause of the initiation of the sequence of events.

I would definitely expect follow up questions when a plain reading of my description of the scenario doesn’t quite line up with the mechanics of the machine involved. In this case, the engine stalled but the hydrostatic transmission was not disengaged. A hydrostatic transmission is a variable displacement hydraulic motor. The difference between a variable displacement hydraulic motor and variable displacement hydraulic pump is the motor has pressurized hydraulic fluid forced into it causing a shaft in the center to turn, whereas a variable displacement hydraulic pump has rotational force applied to the shaft in the center which causes hydraulic fluid to flow. So with a hydrostatic transmission, when the engine powering the hydraulic pump that powers (is forcing fluid into) the transmission stalls on a slope sufficient to cause the machine to roll, the hydrostatic transmission (hydraulic motor) acts as a hydraulic pump, forcing hydraulic fluid back through the hydraulic system. There is quite a lot of resistance to that fluid flow within the system so while it may roll, a true freewheeling situation absent a multi-speed gearbox being shifted to neutral (as would be the case with a tractor) or manual actuation of a hydraulic bypass (as is the case with most mowers that lack a gearbox downstream of the hydrostatic transmission) doesn’t make sense mechanically. Without a neutral or hydraulic bypass, hydrostatic machines are very difficult to free roll.

Not saying what you describe didn’t happen. But when you describe something that doesn’t make sense, you should expect questions.

You’re quite likely to find solutions to problems here, particularly if you are willing to answer legitimate follow up questions, but it sounds like you’re fishing for evidence for a lawsuit rather than a solution to a problem. If that’s the case, good luck to you.

 

[GreensvilleJay]

re: The tractor almost killed me

No, YOU almost killed yourself ! While I don't have your riding mower, every on I've owned for the past 6 decades had a page or two on how to cut grass on a hill. Going sideways is THE way to kill yourself. You found that out not once but TWICE !! It's NOT the tractor's fault.
With only 64 hours on a 10 year old machine, I'd have to see WHY the brakes didn't work. NIW comment was to the point, the brakes should have stopped you. Perhaps they need adjusting ?? HST units do not 'free wheel', unless you push or pull a lever. Similar to automatic transmissions when in gear, they 'auto brake'....
The BIG question for me is WHY did the engine stall ? Was the rider low on fuel? Was the hill steep ? How old is the fuel ? When were the filters changed? Again only 64 hours and the engine 'stalled' would be a 'red flag' for me. My BX23S, 5 years old ,has almost 1000 hours on it and has never 'stalled', even on the 'billy goat path'.

 

[North Idaho Wolfman]

ONE WARNING and nothing more!
I'll give you till the end of the evening to apologize to everyone!

I asked you a simple question about the brakes and you rip me a new one, Not acceptable!

 

[RCW]

Interesting... would YOU be insulted if someone stated the obvious?

Not what I expected here... nor even close to what I asked for. I'll let this ride for a week and see if I get any real answers... then all y'all are welcome to continue doing whatever you do. As yes... I was surprised he was listed as a moderator... far from professional. My comments were emotional. The tractor almost killed me. Get it... ALMOST.

JanB - -

Obviously your comments were emotional, as your tractor did some things that could have caused serious or mortal injury to you.

So sorry you've had this experience, and thankful you are okay.

That said, the owner/operator of any machine has the ultimate responsibility to operate any machine within the parameters of its operator's manual.

I don't see Wolfman's reply adverse at all.

I have no experience with a GR2120.

All I can fathom is that there are some "steep" situations whereby the engine could be starved for fuel, causing the engine to stall.

Similar, some engines can lose lubrication on steep slopes, causing the engine to fail.

Again, covered in the owners manual.....

I own a 70 year old farm tractor that WILL kill you if you're not thinking. I've driven it 50+ years...it hasn't gotten me......yet.

Machines anymore are engineered to protect the operator and bystanders.

I don't discount your claim one bit, but I would look back at your operator's manual.

Best wishes to you.

 

[GreensvilleJay]

curious, I downloaded the current owners manual ( tractor data says last made in 2014....) so the OP's riding mower may be new.

in the 'safe operations'....section...

7. Never "freewheel". Do not let the machine travel
downhill with HST pedal at neutral position.

That implies that in 'neutral' that the HST 'bypass' is in effect, something that is totally unexpected to me. perhaps other owners of that riding mower can confirm/deny this is true ?? I've had an HST that went into 'freewheel' while in neutral ALWAYS had to push or pull some lever.

 

[NCL4701]

curious, I downloaded the current owners manual ( tractor data says last made in 2014....) so the OP's riding mower may be new.

in the 'safe operations'....section...

7. Never "freewheel". Do not let the machine travel
downhill with HST pedal at neutral position.

That implies that in 'neutral' that the HST 'bypass' is in effect, something that is totally unexpected to me. perhaps other owners of that riding mower can confirm/deny this is true ?? I've had an HST that went into 'freewheel' while in neutral ALWAYS had to push or pull some lever.

So if the engine stalls, operator doesn’t use the brake, AND allows the pedal to go to and stay in the neutral position it would freewheel. Interesting.

 

[The Evil Twin]

Wolfman: I would not expect such a flippant comment from someone identified as a moderator. What a dick expression. Of course I tried the brake... NOTHING happened.
You make these decisions and do the deed when the entire accident took less than 5 seconds.

Geeesh. If this is what I can expect from this site... I shall eliminate my account and chalk this up to more bullshit forums to avoid.

The looking glass goes both ways.
Newbie comes in, makes claims to how something tried to kill them or blew up, gets snippy....
I get that you are looking for answers and help. It just might be better if done a little differently.

 

[CiscoRanger]

curious, I downloaded the current owners manual ( tractor data says last made in 2014....) so the OP's riding mower may be new.

in the 'safe operations'....section...

7. Never "freewheel". Do not let the machine travel
downhill with HST pedal at neutral position.

That implies that in 'neutral' that the HST 'bypass' is in effect, something that is totally unexpected to me. perhaps other owners of that riding mower can confirm/deny this is true ?? I've had an HST that went into 'freewheel' while in neutral ALWAYS had to push or pull some lever.

Great find. If only he’d come in with a softer approach he’d have found a lot of help. of all the forums I’ve been on from ford to GM to VW to bobcat, this one is far and away the best, with the best folks.

 

[lmichael]

That whole thing flies in the face of how we all know/expect a hydrostatic trans to operate. With the Kubota, I have now owned 3 hydro machines total (Honda 4514, Simplicity Sovereign and now the Kubota) (not counting my Honda HRX216 walk behind which actually has a mini hydrostatic trans). Anyway not a single one could "freewheel" in the so called "neutral" position. Even so far as I did (due to my own carelessness) have a stall out on the Simplicity on a steep part of my culvert. That beast just stayed right there. Every one of them (though I don't know where it is on the Kubota) has/had a "switch" to "turn on" free wheeling. I cannot imagine the 2120 is different. As in all cases the operator manuals referred to the "center" position as the "neutral" position. Not because it was free wheeling but because the machine was not propelled in either direction.

 

[lugbolt]

Used to (unfortunately) own one of those. The earlier version (GR2100). Briefly I might add!

Hillside mowing, MUST be done up and down, never sideways. Don't matter what mower you're on, if you mow sideways, something's gonna happen at some point. 4wd is nice but it only solves ONE minor problem on hills-forward and reverse traction. Sideways? Solves nothing

You need to seek an attorney.

 

[North Idaho Wolfman]

Well I guess JanB just came on here to insult some of us, I'll give it another day then it's off to the dumpster as I don't see much useful info in this thread.

 

[NCL4701]

I’m thinking the only thing JanB was looking for was evidence to bolster a lawsuit and anyone that answered, “Yeah, that happened to me, too!” would have gotten a subpoena to be deposed.

 

[sitric]

I’m thinking the only thing JanB was looking for was evidence to bolster a lawsuit and anyone that answered, “Yeah, that happened to me, too!” would have gotten a subpoena to be deposed.

^^^^^ exactly what I thought from the beginning. I do think there was some good contributions as to the inner workings of hydrostatic transmissions making the thread not a total waste.

 

[JanB]

Used to (unfortunately) own one of those. The earlier version (GR2100). Briefly I might add!

Hillside mowing, MUST be done up and down, never sideways. Don't matter what mower you're on, if you mow sideways, something's gonna happen at some point. 4wd is nice but it only solves ONE minor problem on hills-forward and reverse traction. Sideways? Solves nothing

You need to seek an attorney.

Getting attorney's involved is always a lose-lose situation because THEY are the only people who ultimately win. Yep, this is something I shall not do. But I would like to know what happened. Some other folks have talked about what has happened to them, but only that when the engine quit, so did the wheels not move. As I thought it should be. Many others are stating the common practice... Up and Down only. Most certainly that is what I was doing and was going up when the engine stalled. The dealer told me most tractor deaths happen when tractors are going backwards. Think about it and it makes sense. Almost impossible to jump off a vehicle that doesn't have ROPS. But again, involving an attorny... not gonna happen. I just hope Kubota makes good on owning the anomaly and helping me change to a BX series with ROPS from the GR series that does not. If caca happens again... as long as I buckle my seat belt... things wouldn't be quite so dangerous in the hills. Small slopes are another issue and where to draw the line. I am certain there is a percent grade definition somewhere.

Thanks for the comment.

 

[JanB]

No.

If I went through a traumatic situation where I almost killed myself (and I have) I would want to analyze and have some feedback on how to avoid a similar result that might actually kill or seriously injure me in the future even if that feedback included some question of operator error being a component of the result, albeit possibly not the proximate cause of the initiation of the sequence of events.

I would definitely expect follow up questions when a plain reading of my description of the scenario doesn’t quite line up with the mechanics of the machine involved. In this case, the engine stalled but the hydrostatic transmission was not disengaged. A hydrostatic transmission is a variable displacement hydraulic motor. The difference between a variable displacement hydraulic motor and variable displacement hydraulic pump is the motor has pressurized hydraulic fluid forced into it causing a shaft in the center to turn, whereas a variable displacement hydraulic pump has rotational force applied to the shaft in the center which causes hydraulic fluid to flow. So with a hydrostatic transmission, when the engine powering the hydraulic pump that powers (is forcing fluid into) the transmission stalls on a slope sufficient to cause the machine to roll, the hydrostatic transmission (hydraulic motor) acts as a hydraulic pump, forcing hydraulic fluid back through the hydraulic system. There is quite a lot of resistance to that fluid flow within the system so while it may roll, a true freewheeling situation absent a multi-speed gearbox being shifted to neutral (as would be the case with a tractor) or manual actuation of a hydraulic bypass (as is the case with most mowers that lack a gearbox downstream of the hydrostatic transmission) doesn’t make sense mechanically. Without a neutral or hydraulic bypass, hydrostatic machines are very difficult to free roll.

Not saying what you describe didn’t happen. But when you describe something that doesn’t make sense, you should expect questions.

You’re quite likely to find solutions to problems here, particularly if you are willing to answer legitimate follow up questions, but it sounds like you’re fishing for evidence for a lawsuit rather than a solution to a problem. If that’s the case, good luck to you.

Thank you. Your reply is most informative. I have learned a great deal and must print this so I can retain your wisdom. Now I need to learn more about both types of systems. Again, I am NOT FISHING for anything to hold as evidence. I responded to another about that... and I shall NOT go the attorney route. I really want to know what went wrong. Riddle me this... I would imagine most of the people in this forum have been driving for many years and just what is the first reaction a drive has when confronted with an emergency situation. Yep, you hit the brakes (unless your learned driving where snow and ice are on the ground for several months, like I did.)

I guess I didn't make it perfectly clear that I was mowing UP and Down the hill. Had this happened while going down the hill steering would have been much easier... as a way to bleed off speed or even get off the darned thing. But it all happened in only a few seconds and going backwards. At least I tried to take an angle... but one thing for certain... the GlideSteer really does turn on a dime (that is not is Mr. Rococo's pocket. [some will get that humor])

Again, thanks so much for the lesson. Tis exactly why I posted my situation. I have a better understanding of what I need to research.

Good news is the dealership FINALLY will be here to pick it up on Monday morning. Then... who knows how long it will be... I'll probably be making hay before getting back to mowing.

Cheers and thanks again. Great stuff.