MX5100 Jerky 3pt hitch

   / MX5100 Jerky 3pt hitch #1  

3boys865

Silver Member
Joined
May 4, 2012
Messages
104
Location
East Tennessee
Tractor
Kubota L4240HST
Purchased a new MX5100 a couple of weeks ago and want to know if any other MX5100 owners have experienced a jerky 3pt hitch? With a box blade on the 3pt, it is smooth when lowering and when raising quickly, but if you raise slowly, the hitch is pretty jerky. Jerky enough to bounce the tractor and make it very difficult to feather up the blade when grading.

Here is a link to a video showing what happens when raising the box blade slowly. MX5100 - YouTube

Is this typical for a MX5100?
 
   / MX5100 Jerky 3pt hitch #2  
Unfortunately, in my experience, yes. I have an MX4700 bought in Dec 2010. The 3pt acted just as you show on your video. Really annoying and even dangerous in some situations. Dealer tried to work with me and had tractor at shop for almost a month and even had BIG KUBOTA in to look at it. They tried adjusting the 3pt control valve, replaced the 3pt control valve and even tried a similar valve from a different tractor. Nothing improved the situation without causing other problems. The thinking was the output of the hydraulic pump, in gallons per minute is so high, and the volume of the single 3pt cylinder is so low, that it abruptly jerks the hitch up in increments instead of the nice, steady, slow rate you might expect when moving the control lever slowly. Instead of a steady, slow movement, it jerks up, then off, then up, then off.....

I finally installed a Pressure Compensating Flow Control Valve after the loader valve, but before the 3pt control valve. (Fluid goes to loader valve first, then 3pt, then rear remotes if installed.) I can reduce the amount of flow going to the 3pt (with excess dumping back to tank). So by adjusting the flow control valve I reduce the amount of fluid going to 3pt, it moves more slowly and much more smoothly. This also reduces flow to the rear remotes. I use that too when I have my snow blade on the FEL. The power angle is connected to rear remotes. By reducing the flow I can get the angle to change at a nice controlled rate instead of slamming back and forth or needing to be very delicate with the control lever. I really like the mod so far. It is a work around, not a fix, but has been more than sufficient for me. I only spent about $150 total, all bolt on, can be removed if needed. Also, this does not affect 3pt lift capacity, just speed, and if I set the flow control at the max setting none of the fluid bypasses and everything works like stock. The pressure drop across the valve I installed is less than 100psi at all flows and pressures so heat build up, pump wear, etc., should never be a problem.

Search for "Jeff's Homebrew Jerky Hitch" on this forum. I pretty much stole his idea that he used on a different tractor. If you are seriously interested I can give more specific info, pictures, etc....

Best of luck. The flow control valve and hydraulic top link are the best additions I have made to the tractor.

Wxman
 
   / MX5100 Jerky 3pt hitch #3  
My personal MX5100 is very smooth in operation. Weird how one can be fine and another not, yet they can't diagnose the issue.
 
   / MX5100 Jerky 3pt hitch #4  
i had an L3800 THAT DID THAT i traded it in on a 7040 that doesnt have the jerky hitch
 
   / MX5100 Jerky 3pt hitch #5  
My MX5100 is jerky going up the first (and sometimes 2nd) time when it is below freezing outside. Once the warm fluid gets in there, no problem.
 
   / MX5100 Jerky 3pt hitch #6  
Don't get me going
 
   / MX5100 Jerky 3pt hitch #7  
Yeah, my MX5100 has this "undocumented" feature also. It doesn't matter if the hydraulic fluid is cold or warmed up. I test drove a MX4700 HST and it did it also. Dealer said it wouldn't after the fluid warmed up, but we all know better don't we.

HP
 
   / MX5100 Jerky 3pt hitch #9  
Mine seems fine. No problems so far, but only 6 hours on it. Ill be watching.

If it was going to do it, it would have already done it. I used to own an L3400... it would almost jerk the front wheels off the ground with my ballast box on the rear and if you try to raise it slowly.. There are dozens of thread on the Kubota jerky 3pt hitch thing.. Here is my impression. the Older L3400/L2800 the majority of them have the jerky hitch thing to one extent or another.. the Newer L3200/L3800 seem maybe less than half have the problem.. Many owners report no problems. The L4700/L5100 seem to have even less incidence of the syndrome. You can read for days if you want to search for "jerky 3pt hitch". We have heard of a few people getting them fixed thru dealers but no one can explain how it was done. I messed around for months trying to get a couple of dealers to fix it, but long long story short.. no fix. Kubota Corporate called me after I traded it for a Kioti, and they said, well, since you don't own the tractor anymore... not much we can do..This is after months of trying to get the district manager thru the dealer to take an interest. Chilly807 and LD1, two good mechanics tried their best.. The fix is worse than what they were trying to cure. So bottom line if you have the problem, well you have a problem if it bothers you.. If you don't, your fine. Grand L's do not have the problem. Only some of the Standard L's.. as time goes on we see less and less complaints..But like yours it still rears its ugly head from time to time. Good luck

James K0UA
 
 
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