3-Point Hitch L-series Jerky 3PH - Jeff's homebrew repair.

[Notforhire]

I do apologize for the sarcasm. I read about many issues on different makes and models of tractors on this forum. When enough people write about the same problem, you know it's not just one or two machines. Be it John Deere, Kubota, or others, the same problems seem to go on for years. The manufacturers can't not know that these problems exist, the reporting is too widespread. I don't expect these tractors to be perfect, but repeat problems should be dealt with.

Sorry for the rant. Is it still brand bashing when you bash them all?

Anonymous tractor owner

 

[rScotty]

just read that John Deere is discussing in high level meetings how much they can save if their tractor pistons and crankshafts are made of plastic. Just like their tractor's hoods and fenders, the change can be further marketed as parts that will never rust ! ....................I'm sorry, of course I'm kidding!

I hope so! After all, our old fashioned aluminum pistons don't rust either.

Something has been bothering me about these problems with the jerky 3 pt hitches. I don't know quite why, but so far I've not heard of any of the tractor owners taking the time to redesign that simple hydraulic system so that it doesn't jerk. Doing so would probably require the thinking cap, and maybe making a few parts, but it shouldn't be all that hard to improve. Lots of tractors have smooth 3pts. It's the jerky ones that are the oddballs. Why is that?
rScotty

 

[scottcampthomas]

We were hoping the manufacturer would "take the time to redesign that simple hydraulic system "

 

[scottcampthomas]

Notforhire, No apology needed. Picking a tractor that does everything better than every other tractor is impossible. One could choose any of the top brands based on the specific job intended or features and strengths needed and it still won't be the perfect tractor for them, just the closest to the perfect tractor for them.

 

[rScotty]

We were hoping the manufacturer would "take the time to redesign that simple hydraulic system "

That's exactly what puzzles me. The manufacturer hasn't shown any interest in doing so; these particular tractors are popular in spite of the lack of support. We already know it can be done because there are plenty of other brands with essentially the same system and they don't jump.

So.....there's an opportunity for someone else to do it.

I keep hearing that opportunities aren't all that easily found and that one looks like a good one. So why isn't it happening for tractors. ?
When I look at other mechanical things like trucks, hot rods, airplanes, boats they all seem to have all kinds of aftermarket improvements for just about every system. But not tractors. Tractors improvements seem to be mostly buckets and implements. It just seems kinda strange.
rScotty

 

[Nickanto]

Mine isn't jerky unless at low rpms

 

[scottcampthomas]

if you are sure this mod is worthwhile, please contact Denis Hood at Kubota 770-995-8855 ext 2910 . He and Kubota engineers have been looking into this problem.

 

[Chilly807]

That's exactly what puzzles me. The manufacturer hasn't shown any interest in doing so; these particular tractors are popular in spite of the lack of support. We already know it can be done because there are plenty of other brands with essentially the same system and they don't jump.

So.....there's an opportunity for someone else to do it.

I keep hearing that opportunities aren't all that easily found and that one looks like a good one. So why isn't it happening for tractors. ?
When I look at other mechanical things like trucks, hot rods, airplanes, boats they all seem to have all kinds of aftermarket improvements for just about every system. But not tractors. Tractors improvements seem to be mostly buckets and implements. It just seems kinda strange.
rScotty

The trouble is, I think its a fundamental design problem with the way the linkages inside the case control the movement of the position control valve. There's lost motion and slop in the system, which is where some of the jerkiness originates. Without a major redesign of yhe transmission case there's no easy way to fix it. You can make the best valve in the world, but if it's not opened and closed smoothly you'll have rough operation. When I had mine apart I was considering adding some springs to the internal linkages to hold everything in tension, then I thought about what one loose spring would do to the transmission if it didn't stay in place. I got cold feet and said "The **** with this, it's not worth risking serious damage "

Sean

 

[k0ua]

The trouble is, I think its a fundamental design problem with the way the linkages inside the case control the movement of the position control valve. There's lost motion and slop in the system, which is where some of the jerkiness originates. Without a major redesign of yhe transmission case there's no easy way to fix it. You can make the best valve in the world, but if it's not opened and closed smoothly you'll have rough operation. When I had mine apart I was considering adding some springs to the internal linkages to hold everything in tension, then I thought about what one loose spring would do to the transmission if it didn't stay in place. I got cold feet and said "The **** with this, it's not worth risking serious damage "

Sean

Sean if you could re-design that thing, there would be songs sung about you.. TBN hall of fame and all of that, man.. think about it.

 

[Chilly807]

Sean if you could re-design that thing, there would be songs sung about you.. TBN hall of fame and all of that, man.. think about it.

Yeah.. The springs would be a band-aid fix at best. The case is so compact there's no room to add much. Longer levers on the linkage would help, but there's no room to swing them. It needs a redesign to truly get fixed, and that's not happening anytime soon.
Sean