3-Point Hitch Another L3700 with Jerky lift

InThePines · Aug 27, 2010

Ok, I have read the threads on this and it seems a problem was corrected years back on L3400. I have even watched the video and seen what it was like. I have a new L3700 with 19 hours. Fast and moderate lift speeds are fine, but when I try to do small position adjustments for a box blade for example, it gets pretty jerky. FEL is smooth. Is this something I just need to accept or should I press my dealer? I have better luck lifting fast and lowering slowly than trying to lift in small increments.
Thanks for your advice.

SmallTimeCountry · Aug 27, 2010

My 3700 does the same thing. I'll be interested in hearing what others have to say about this.

Code54 · Aug 27, 2010

Very true, mine is anything but smooth also.... Nice machine and really this is one thing they should work on a bit. let us know what you fine out of yo press it

ritschner · Aug 27, 2010

What is the setting of the three point lowering speed knob? If the setting were all the way open for high speed lowering and there was any play in the control lever linkage, it seems it might cause the jerkiness described.:confused3: It might be worth a try adjusting the setting. Otherwise it may be the adjustment of the three point system itself.

montelatici · Aug 27, 2010

ritschner said:
What is the setting of the three point lowering speed knob? If the setting were all the way open for high speed lowering and there was any play in the control lever linkage, it seems it might cause the jerkiness described.:confused3: It might be worth a try adjusting the setting. Otherwise it may be the adjustment of the three point system itself.

I don't have a jerky 3-point the brush hog but I keep the lowering speed knob on a very slow setting.

InThePines · Aug 27, 2010

montelatici said:
I don't have a jerky 3-point the brush hog but I keep the lowering speed knob on a very slow setting.

Thanks for that advice. I tried it just now, and I still have the problem when lifting. I have tried different settings on that speed knob and it does slow the release, but does not help with the lift. I hate to trailer it up.....

Harvest Moon · Aug 27, 2010

I've tried to solve this problem with my L3400 but have had limited success. My machine was among the early machines offered with a basic position control valve. The only known fix was to upgrade to a better valve, which I did. It improved things but it's still not smooth.

Later versions of the L3400 included the upgraded valve standard. But then there were reports of another valve change, and for some it seemed a step backwards towards the earlier valves performance.

It appears that the hydraulic cylinder used in the L3400 is too small for the flow rate delivered by the valves, which were originally used in earlier pre L3400 model tractors with larger cylinders.

The L3700, likely has the best of the L3400 valves but also likely has a higher flow rate than the L3400 and therefor is likely even jerkier. I'd love to see a video, there are several posted of the L3400 with different valves. It would be interesting to compare.

When I bought my tractor, it was marked as a "standard tractor." When I sought help, I was told: Sorry, you bought an "economy" tractor. Worse now, the L3700 is marked as an "economy" tractor. So, best of luck to you all.

montelatici · Aug 27, 2010

Harvest Moon said:
I've tried to solve this problem with my L3400 but have had limited success. My machine was among the early machines offered with a basic position control valve. The only known fix was to upgrade to a better valve, which I did. It improved things but it's still not smooth.

Later versions of the L3400 included the upgraded valve standard. But then there were reports of another valve change, and for some it seemed a step backwards towards the earlier valves performance.

It appears that the hydraulic cylinder used in the L3400 is too small for the flow rate delivered by the valves, which were originally used in earlier pre L3400 model tractors with larger cylinders.

The L3700, likely has the best of the L3400 valves but also likely has a higher flow rate than the L3400 and therefor is likely even jerkier. I'd love to see a video, there are several posted of the L3400 with different valves. It would be interesting to compare.

When I bought my tractor, it was marked as a "standard tractor." When I sought help, I was told: Sorry, you bought an "economy" tractor. Worse now, the L3700 is marked as an "economy" tractor. So, best of luck to you all.

Actually the term is "Special Utility", hence the SU nomenclature. :laughing:

ccsial · Aug 27, 2010

When I got my 05 L3400 the 3PH would jump about 1 inch at a time. The dealer changed the valve and it now jumps just a bit under 1/4". It made a big difference in being jerky but it is not as smooth as my ford.

I would suggest putting a ruler or stick back there and measure the jump increment while very slowy raising the control lever. If you are getting about 1/4" I doubt there is anything Kubota can do for you.

k0ua · Aug 27, 2010

Here is what I have found, on my 2010 L3400:
If you raise the lift, in one smooth movement, no problem it will go there smoothly, you then can lower the lift by gently moving the lever down in any increments you like, and it will smoothly go down. However if you "overshoot" the place you want to stop at. you cannot just nudge it back up a little it will jerk up every time. so to summarize: move up to one position, in one movement of the lever, no problem smooth movement up to that position and stop. And to move down smoothly, no problem, you can move in one or multiple movements of the lever, and the movement is smooth. BUT if you try to move up in small increments, Big potential problem, jerky upward movement.
Overall this has not really diminished anything I do with the tractor, I just know how it works and I work accordingly. But is is not smooth up with small movements. YMMV
James K0UA

Harvest Moon · Aug 28, 2010

montelatici said:
Actually the term is "Special Utility", hence the SU nomenclature. :laughing:

I see that you are right. A while back my dealer sent me a promo introducing the L3700 as an "economy" model but a quick scan of Kubota's website and I do not see any mention of the word "economy."

Although, I'd bet that L3700 any owner that complains to Kubota about this problem will hear all about their selection of the "economy" model.

montelatici · Aug 28, 2010

Harvest Moon said:
I see that you are right. A while back my dealer sent me a promo introducing the L3700 as an "economy" model but a quick scan of Kubota's website and I do not see any mention of the word "economy."

Although, I'd bet that L3700 any owner that complains to Kubota about this problem will hear all about their selection of the "economy" model.

Probably, depending on the dealer. Some dealers will bend over backwards to keep you happy, others won't.

teg · Aug 28, 2010

montelatici said:
...Some dealers will bend over backwards to keep you happy, others won't.

I would look into which dealer you have... I'm pretty sure kubota will not replace any valves. I would NOT recommend a tractor with a jerky hitch... SO for those of you LOOKING to BUY.... Try it out before you buy!!! It would have been a deal breaker for me.

I did get my valves replaced and I love the tractor... now. Some of the videos you might have seen were mine. I tried my best to raise the 3ph as slowly as I could - one constant motion. Here they are again....

Before:
YouTube - Kubota L2800 Original 3ph Valves

After:
YouTube - Kubota L2800 After Valve Replacement

I just wish, kubota would allow people to buy the better valve but I guess they wouldn't sell the more expensive units...

SPYDERLK · Aug 28, 2010

teg said:
I would look into which dealer you have... I'm pretty sure kubota will not replace any valves. I would NOT recommend a tractor with a jerky hitch... SO for those of you LOOKING to BUY.... Try it out before you buy!!! It would have been a deal breaker for me.

I did get my valves replaced and I love the tractor... now. Some of the videos you might have seen were mine. I tried my best to raise the 3ph as slowly as I could - one constant motion. Here they are again....

Before:
YouTube - Kubota L2800 Original 3ph Valves

After:
YouTube - Kubota L2800 After Valve Replacement

I just wish, kubota would allow people to buy the better valve but I guess they wouldn't sell the more expensive units...

On the 1st one the tractor is reving. On the second its at lo idle. The output of the pump is therefore much lower and could be masking the same characteristic shown in the 1st video with the original valve. I have the same problem with my L3450 when its reved up. I think full pump flow is just valved to the 3ph lift on these tractors. Every adjustment is a jerk as the motion starts. When you do a long lift there is only one jerk followed by rapid smooth upward motion to the upper setting. That way the jerk is not so noticeable.
larry

teg · Aug 28, 2010

SPYDERLK said:
On the 1st one the tractor is reving. On the second its at lo idle...

I have it several ways... it was the same regardless of RPMs... I was trying to find two videos with the same angle. If you want I can post slow rpm vs. high rpms... the results are the same.

YouTube - Kubota L2800 After Valve Replacement 3PH

YouTube - Kubota L2800 After Valve Replacement 3PH

I have lots of video of it... I have a new video recorder... I'll shoot HIGH rpms with a bucket out on the end of a boom...

InThePines · Aug 28, 2010

Thanks for all your posts. It has been very imformative. My lift is a little worse than your 2nd video. Maybe I am being unrealistic. My old Ford 8N had a very smooth lift and that is what I am comparing to. That second video "after valve" still appeared to jerk the implement a little. I am going to try to record a video, is youtube the best place to load it or can you load a video to this tractorbynet.com site?

Again, thanks for all the replies. I am new to modern tractors...

teg · Aug 28, 2010

I have not uploaded video on TBN... but you can do it here:
TractorByNet.com - Registration

Youtube was easy enough, I could do it... :laughing:

PS... looking forward to seeing them...

Chilly807 · Aug 29, 2010

I suspect your L3700 is pretty much the same as my L3400, 3 ph wise anyway. Mine isn't smooth upwards, but it's live-able. I knew it was going to be that way when I got the tractor, and decided it wasn't enough to make me buy something else.

I doubt Kubota will do much to fix the problem, if they do the floodgates will open and everyone and their dog with a 2800/3400/3700 will be beating on the doors Monday morning. I know I would be.

Sean

TheGoose · Aug 31, 2010

The only problem I have with my lift is when I use a boom/pole type implement. No problem with a box blade or like but that jerking extended out 5-6 feet like a post hole digger is very amplified.

I actually like how the 3 pt performs on the box blade, you don't have to turn around to know you raised it a notch or two.

Using the post hole digger it can swing wildly and uncontrollably. IMO a very bad trait of these tractors I think it is a safety hazard and Kubota should step up to the plate and fix the problem or at least let us upgrade our tractors at a reasonable cost. I might whine to my dealer just to make noise.