Any thoughts about the abrupt stopping characteristic?

doggman

Member
I'm wondering if anybody out there has come up with a cure or thoughts about the abrupt stopping nature of thehydro drive. </P>


Normally, it's not a real problem once you get a handle on the throttle characteristics and pay attention all the time. However, if something unusual happens it can be downright dangerous. </P>


I have had a couple of times, including one bad time, where I let up and the machine screeched to a halt throwing me, my passenger, and the cargo forward. The passenger almost went over the front. In this case I was running DEAD SLOW, pulling into the garage, and it happened. It was like I hit the wall. </P>


One other time I got stung by an insect on the leg while I was running fast. Naturally, I jerked my foot and it was ass-over-applecart. There have been other milder but startling incidents. </P>


Kubota tells me that they had this problem initially and people complained. Then they went to a longer throw lever for throttle/hydro control and it caused more problems because people COULDN'T stop and were running into things. Then they went back to the short lever - and said that's just they way it's going to be - be careful and always wear your belts. Well, I see belts as a means of protection and not to cover a design problem.</P>


I have operated a lot of equipment in my life - old and new, large and compact. Some wereall mechanical drive and linkage, some were pneumatic controls, some hydro, some electric over hydro, etc. etc. A lot of them had quirks, too. </P>


I think the problem is that if Kubota fixes this it's going to put them out of the price point with Polaris, Bobcat, Kawasaki, Deere, etc. And, I think a recall will really hurt them <SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">financially</SPAN> and with their reputation. But I think I would rather tout that my product "drives like a dream all the time " than "it's drives great but watch out for letting your foot off the pedal and always wear your seatbelt so that you don't get thrown...). </P>


How do you fix it? I'm not sure buthere's a couple of suggestions.</P>


1) A separate throttle and hydro control might help. Just like on their tractors - and they have the experience and know how to do this. I have no problems like this on my Kubota 4310 hydro tractor. It's not a perfect solution but it might help. Plus, you can back up in any one of 3 ranges and are not restricted to one reverse range. </P>


2) A modulating dump valve that bleeds the hydro pressure relative to speed, foot pressure, etc. Not too hard to do. Kubota could do it pretty easily - they already have a "float" option on the dump bed for example. </P>


3) I have a Case/IH hydro tractor that also has a regular foot operateddisk clutch. 99.99% of the time I never touch the clutch and use all hydro controls. But if the need arises I can disengage everything by hitting the clutch. That won't solve the Kubota issue but maybe a variation of it would - againrelative to speed, foot pressure, etc. </P>


I have an old 6 wheel JD Gator that I was going to get rid of when I got the Kubota. I wound up keeping it for helpers and guests to drive since the Kubota was tooquirky. (There are plenty of other manufacturers with quality utility vehicles out there. My replacement choice would probably be the noisy Bobcat 2200. But it's got a fuel efficient Kubota diesel, full time 4WD, and no hydro problems...)</P>


My girlfriend is a corporate attorney and she feelsthatKubota (and the dealers) is going to have a problem with this if they haven't already . </P>


Let's hope those stodgy Japanese engineers realize this is an issue and find a cure so that it drives like a normal vehicle with normal predictable compression braking. </P>
 

bczoom

Senior Member
Staff member
Gold Site Supporter
Well, I don't have a cure but will provide my thoughts...

First, I believe the engineers (or a large # of them) for the RTV are from the USA but I'm not 100% sure.

As you noted, it's "normally" not a problem.

I "normally" just live with it but watching my daughter (8 years old) drive it found something that works pretty well. Contrary to everything you were ever taught about driving an automatic, use both feet. She will start applying the brake before fully letting of the accelerator. By doing so, yes... the tranny and brakes are working against each other a bit but she can make a very smooth stop. The brakes are doing the stopping instead of the speed control the way she does it.

As for the being bit by a bee or something, you could loose control of almost any vehicle.

More later.... I'm going outside to take the RTV for a ride.

Brian
 

doggman

Member
I talked to Kubota USrecently and this was the info they gave me. </P>


The problem is addressed in Kubota Service Bulletin 2005-13 for the abrupt stopping issue with the "Fast" linkage. It's not really a recall but, rather,a "Campaign". Sounds like double talk to me. However, the Japanese auto makers are known for their "silent" recalls so I guess it fits. </P>


The "Fast" linkage is on units from Ser. # 24400 to 34500. Slow linkage before and after those Serial #s. However, my dealer said that the current units still have the "fast" linkage. Who knows...?</P>


I haven't had mine changed over yet due to being too busy on my part to trailer the thing 60 miles to the dealer, wait on it, and drive back. There is also some issue as to who will pay for the work as they feel it is not really warranty work... Geez.....</P>


Brian - the one foot on the gas and one on the brake ( sounds like Sammay Hagar to me) does help but it's too weird to do all the time. I always wondered how kids drove these things - your daughter sounds very resourceful. (My parents drove that way and it always bugged me). I can do it if I have to creep a piece of equipment but that's about all I can stand. </P>


And, this is more about the issue of accidentally lifting the foot off the throttle rather than a normal, anticipated stop. </P>
 

bczoom

Senior Member
Staff member
Gold Site Supporter
Doggman,

What they're referring to as "fast" linkage is what we call the "old style".
The "fast" one is on serial #'s 10001 - 24399 and all units over 34500, so yes, your dealer is correct when he says the current units are using the "fast" style.

As for changing the linkage, it's something you can do pretty easily. I did it in about 15-30 minutes. Somewhere out on one of the forums, I posted pics and instructions. I'll find it if you want to do the work yourself. It isn't hard and I would probably just have the dealer send part sent directly to your place.

Yea, I have a hard time using 2 pedals myself.

Brian
 
Top