Hydraulic Auto Height Height setting

[knightgang]

We just bought a Kubota L2950 4x4 compact tractor and a 5' Kodiak Brush Hog. I an new to tractors so bare with me. I have worked other tractors for years, but basic operations like bucket grading and brush hogging, but always with settings that someone else dialed in.

Anyway, I was getting the brush hog all set, rear wheel height, get the stabilizer turnbuckles tightened up, etc. I noticed that on my 3 point hydraulic lift lever, if I pull it all the way back, the deck goes up, but if I push it forward to one of the number settings, the deck will go all the way down.

I eventually just let it fall slowly and then tightened the hydraulic screw under the front of the seat that adjust how quickly an implement will fall. This way I could keep the 3 point arms at the correct height.

I am sure this is not the correct way to do this, but I am not exactly sure how the height adjustment works. I assume that if you put the lever on one of the numbers along the rail, that is supposed to be a predetermined position in the hydraulics.

If I am correct, and my tractor does not move the hydraulics to that predetermined position referenced by the number along the lever rail, then what is wrong with my tractor? Where do I start to fix it?

Thanks

BTW, yes I am a newbie here and I know that forum etiquette says that I should introduce myself somewhere, my I hope you understand I just don;t have time for that post at this time.

 

[ShaunRH]

Welcome to the forum!

I don't think your tractor is broken and you've already figured out some of the cool functions of the 3 point, so you're ahead of the game in many ways.

That nice little number chart on the 3pt lift lever looks precise, but it isn't. It generally ends up being more of a reference item when working with different implements and different 3 point setups, as anything in those setups can change things dramatically.

I can't speak for other operators here but I can tell you how I do things, and right or wrong (if there is such a thing with 3 point positioning) it seems to work for me.

First, I don't expect the same repeatability in height on the down stroke from what I get on the up stroke. Variances in the 3 point system seem to act differently on the way down than on the way up. It probably has to do with movement and binding changes under weight than from under slack conditions. In both conditions, the implement may actually settle out to a slightly different height, so where it starts may not be where it ends up. Keep an eye on the implement and if it settles out, use that as your reference point.

Second, you should have a cool little screw knob on that numbered rail. That is a stop that lets you come down from fully lifted to a known set position. That stop is your buddy but it can be your bane, especially while mowing. If you are using it, MAKE SURE IT'S TIGHT AS HECK! (Caps for emphasis, not yelling) My brothers tractor has one and it slips like crazy. Caused me all sorts of headaches when running a box blade once.

Lastly, be aware that implements aren't precision instruments. You need to always be watching them and correcting them. It's not like a surface planer in wood where you spin the wheel 1 rotation and know you have an exact depth of cut change. Experience with your tractor will tell you how much moving that lever does. Then, you get to learn if you make an adjustment to lift arm mount point, turnbuckle leveling, etc. that everything you learned just went out the window and you have to re-learn the new setup.

So, as long as you move that lever and the 3 point height changes in somewhat smooth increments, there is nothing wrong with your tractor. Now, having said that, there are adjustments for top and bottom responsiveness but I think the dealer has to make those adjustments as part of the setup. They could've missed that so you might want to give them a call and ask them to review it. It is a new tractor right?

 

[Bulldog]

The knob you've been using under your seat is for speed control and also a lock for the 3pt that will keep it from lowering. Basicly you'll set it to the speed you want your cutter to lower and it will stay there. Like ShaunRH said you should have a slide adjustment on your 3pt position control. Depends on what implement you have on at the time will determine where you need to set the stop at. My rotary cutter is around 7 but my finish mower is around 3. You'll just have to mess with it and see what works for you with each implement. When I set mine I'll lower the control down to the height I need and then slide the lock up to the control, then tighten the knob down. Raise your implement and lower it back to the stop to see if it's needs further adjustment. If not you're ready for work if it does then make the adjustments and test again. Once you have done this a few times it will be second nature and you'll be ready to help someone else thru the same thing.

 

[knightgang]

ShaunRH, no it is not a new tractor. Bought this used from a dealer, it came in on trade. Looks great, '93-'96 model with 3400 hours.

I guess I will just have to play with the levers a bit to figure out the particulars on this tractor. It just seems that when I pull the leaver to say where #8 position is, it will still go all the way down. The hydraulics are strong and smooth. Whatever it is, it must be something simple that I have just overlooked or at the very least just have not quite figured things out yet....

Thanks for your input guys....

 

[North Idaho Wolfman]

First go here and download the OPS manual for your tractor, will help with all the adjustments and levers.
http://www.kubotabooks.com/AutoInde...df&AutoIndex=0c6a51c1a190a07c3b82574c16fd6f3b

I'm also sending you a link via PM (top right) for a download of the WSM for your tractor, I have the same tractor just slightly larger and it has the same controls as yours, it has proportional hydraulic control so if it's dropping all the way on any movement of the lever then something is wrong, I'll bet the feed back rod is either out of adjustment or broken/gone.

 

[knightgang]

First go here and download the OPS manual for your tractor, will help with all the adjustments and levers.
http://www.kubotabooks.com/AutoInde...df&AutoIndex=0c6a51c1a190a07c3b82574c16fd6f3b

I'm also sending you a link via PM (top right) for a download of the WSM for your tractor, I have the same tractor just slightly larger and it has the same controls as yours, it has proportional hydraulic control so if it's dropping all the way on any movement of the lever then something is wrong, I'll bet the feed back rod is either out of adjustment or broken/gone.

You refer to the proportional hydraulic control, is this the same as the positioning control valve?

On page S8.17, I see the reference to feedback lever shaft. However, I do not see anywhere exactly what it is connected to or how to adjust it.

The good news is that once I figure out how to adjust it or reconnect the rod, it seems like a simple fix.
Can you provide any other details on the feedback rod, what are its two connection points and how to adjust it?

My apologies for asking for an overall repair strategy without providing any additional feedback from my own investigation and trouble shooting based on the previous posts and the repair manual. It has been raining here and we have work and football games tonight, no real time to look and investigate before tryign to go use the tractor in the woods Sat morning.

Thanks again.

 

[North Idaho Wolfman]

This is the feed back rod, and the yellow will be where you adjust it.

 

[knightgang]

Okay, so I thought that was the feedback rod. I have it adjusted all the way to the end and it seems to be working correctly. If it ever needs any more out adjustment, I will have to add length to the rod.

However, it brings me to another issue. The lift links that go from the upper hydraulic arms to the lift arms I think are to long for this tractor. The look like the are modified center links (shorter ones) and they are both adjusted as short as they will go.

That said, I have the rear wheel of my Kodiak Rotary Mower adjusted to the second to the highest height (lower cut) and when I lower the deck to position seven, it is level. By level 5, the front of the deck is on the ground.

I am going to look through the manuals you provided to get OEM part numbers for these links and find out what the OEM length specifications are. I think that will get me 100% in full operation.

 

[North Idaho Wolfman]

I have the same model just one size larger, give me a picture and the measurements and I should be able to tell you what is going on with it.

 

[knightgang]

I did not get pictures as I have been dealing with a flat tire and a worn out (broken) lift arm ball socket.

However, I did measure the length of the lift links and at the shortest they measured 18". Both of them are modified Center links and they maintain adjustment.

I am considering taking them off and shortening the center section of each of them. By guess is that I need to take about 3" out of each one.

Wolfman, if you will let me know the proper lengths, then I can determine what actions I am going to take to correct this issue.

Thanks

 

[knightgang]

Wolfman, here are the pics. As you can see, the lift arm links are re purposed Center Links. At their shortest position, they are 18" Long c to c at the attachment points. I believe that this is about 3" too long.

I did not take measurements of everything, however by my rough calculations, the lift arms are about 2'6" long. The Pivot point of the lift arm at the axle is set back about 3" form the end of the Lift link point on the Hydraulic arm connection. Assuming that the lift link attaches to the lift arm at about 12" from the axle pivot point and that it is another 18" to the end of the Lift arm, 3" in the length of the Lift arm link can make a difference of almost 10" at the end of the link. (See attached Diagram)

Wolfe, if you can let me know what the measurements are supposed to be for the Lift arm links, I will be able to get full travel out of my 3 point as intended.

Thanks

 

[North Idaho Wolfman]

I'll have you some measurements in a couple of days.
My tractor is on a job right now and I'm not there.

 

[Bulldog]

I measured the links on my L3000, they are 17" from C to C. These are the factory links by the way.

 

[North Idaho Wolfman]

I measured the links and they are 16" 17" and 18", they have three holes in the bottoms.