Yanmar YM2500 3pt Photos and Description

joe_padavano · Jul 10, 2005

Well, here's where I'm not quite sure whether the YM2500 and the JD850 are exactly the same or not, but here goes...

The hydraulic system uses the transmission oil, so the trans dipstick on the top of the gear case (in front of and to the right of the shifter) will be where you want to check. Proper technique for checking the level is to unscrew and remove the dipstick, wipe it off, then insert it until the bottom of the screw portion sits on the top flange of the opening. Do not screw it back in - read the level at this point.

The hydraulic filter is actually a screen on the underside of the trans case. Look on the bottom on the left hand side and you'll see a round cover, about 2" or so in diameter, held on with two bolts to a cylindrical feature on the bottom of the case. Remove the bolts and you'll need to pry and tap the cover off to overcome the friction of the o-ring. Oh, and be prepared for 20 quarts of hydraulic fluid to come gushing out once you pry the cap off. The filter screen is a cylindrical unit under the cap about 2" in diameter and 6" long. If it's not clogged simply wash it out with solvent and reinstall it. Put the cap back on (being careful not to pinch the o-ring) and refill the trans through the dipstick hole.

As I said, this is how the 850 works. I think the YM2500 is the same, but I don't know that for sure.

One more thing - JD recommends changing the trans fluid every 100 hours.

Joe Padavano

wlm007 · Jul 16, 2005

Thanks for the help which was also a bit of encouragement. Nothing like going into the unknown blind. I got the oil changed and the filter cleaned. Man was it trashy. The screen was really clogged which I'm sure affected the system's operation. The sump had a plug so I was able to catch the old oil and not have it blow all over me, tractor and dirt. Nothing like working in the dirt with oil everywhere. I'm sure the green people appreciate it also. I got it all back together and didn't have to adjust a thing. I bush hogged for four hours and it worked perfectly.
Thanks again,
Lynn McMahan

chriswheeler · Jul 17, 2005

I gave Joe's John Deere 850 adjusting method a try this weekend. Started out by removing the landscape rake I had on the 3 point. Then put lever #5 all the way down. ( handle is almost horizontal) I raised the lift all the way up with the hyd. lift control lever. I could still lift the left arm almost 2 inches by hand?? ( spring still atached ) Question here might be the .25" - .40" be with the spring off?? Guess that is the next thing to try. Fairly sure it works because I removed the cotter pin that holds the arm rod to the end of the crank at the center of the lift arm, on it's own it lifted another 2" or so. Returning the rod to the hole in the crank dropped the 3 point the same 2". Have to take that as a good sign. Ran the landscape rake on the drive plucking tumble weed out of the drive, a few passes does a great job. Lever #5 in either position didn't make a difference except that with the lever all the way up it did hold position better. I'm guessing here, but the tractor might only use draft control with a heavy load like a plow or the box blade on uneven ground. With little rise and fall and a small load there might not be enough movement in the 3 point to cause a reaction with the draft control. Guessing that because I'm on flat ground that there isn't enough of a rise and fall to cause it to work?? Have some work to do with the box blade next week that should load the 3 point a little better, see what happens there. Thanks for all of the help so far, still playing with this thing some, not quite dialed in.
Chris

joe_padavano · Jul 17, 2005

Chris,

Glad to help. Hope you get it fully dialed in. I should note that the 850 does not have "Lever 5", there's just a plug there where the lever would have been. Don't know what this means.

Joe Padavano

chriswheeler · Jul 17, 2005

I understand that the YM 2500 is "about" the same as the JD 850 and the YM 3000 is "about" the same as the JD 950. What the differences are, unknown to me. I do know that my YM 3000 is exactly the same as the YM 2500 in the pictures posted. I also understand that "Draft Control" is not found on most of the smaller Yanmars. Think that the majority of the Yanmars in this country are the smaller units without it, perhaps this is why the subject doesn't come up with Yanmar very often.
Chris

kenmac · Jul 17, 2005

I have a 3110 and still don't understand the draft control, or if mine even has draft control. I thought that if you had a box blade on any unit that the lift arms would raise up & down witthe contour of the ground.

wlm007 · Jul 17, 2005

kenmac-If I'm reading you right; When I set my box blade or tiller at a certain height, it's set. One thing that I had to learn early was if I cross a depression, like a ditch and the attachment bottoms out (front of tractor goes up attachment goes down) then often times I'm stuck. If the attachment is not all the way up I can lift it up and back out. As far as I know the attachment stays parallel with the tractor and does not float.
Lynn McMahan

kenmac · Jul 17, 2005

I don't know of anything that would keep the lift from comming up. Isn't the weight of the attatchement the only thing keeping the lift arms down?I know on my 3110 that if I want to move a mound of dirt ,that I have to add weight to my box blade to keep it down,other wise ,it will ride over the the mound of dirt. I haven't tried lever # 5 it may lock the 3 point in the down position where it won't raise up without adding weight. On my 3110 with the tractor running and the lift in the down position (no attatctements connected) you can raise the lift arms up.

chriswheeler · Jul 23, 2005

Hi all,
Put the box scraper on this morning and did a little work. Wasn't able to detect any noticeable difference in function with draft control engaged and disengaged. Only difference seams to be that the implement will stay put better with lever #5 in the upper position than the lower. I bet one might notice a difference in function more if you were pulling a plow. Thanks for the help,
Chris

neflfarmer · May 29, 2012

I know this is an old post, but for anyone finding it like I did I have some additional info that would help this already very valuable thread.
I have a 2500 that I bought recently and it had a similar problem as originally posted. Setting the draft control would hold the 3 pt for a while then drift down after bumping around a bit. I found that the lock screw that goes through the draft control handle was missing, but the handle would stay relatively at the same place despite this. But it was very touchy to get the height adjusted properly. So after reading the manual and looking at the 3 pt control valve assembly I found that the square bar that pushes on the "button", (hydraulic valve for 3 pt) was gunked up with grease and debris, A cover should be covering this normally. So I cleaned up the mechanism in this area and lubed it up, (motorcycle chain lube is great! it seeps in then sticks well). After doing this, the draft control handle would spring back quickly as it should. I then added a screw/washer/wing nut on the lever to be able to lock it in position. I then cleand and reinstalled the knob under the seat that locks the hydraulics, and the speed control handle. They worked now too.
Now the trunbuckle. It is part of the "feedback mechanism". The purpose is to ensure that when the height is set by the draft control, if the arms try to lift, it opens the hydraulic valve to try to lower the arm, it they try to fall, it raises the arms. Hence the name feedback control. If the turnbuckle is mis-adjusted, two things can happen, the arms will float too much, or the worse case, it will constantly be trying to raise or lower the arms by pushing on and releasing the "button" applying negative/positive pressure to the rock shaft. So if it is too tight it will constantly be lowering or raising the arms and therefore will make the pump work harder, or force hydraulic fluid through the bypass valve. Both bad. This is because of the cam shaped metal plate on the rock shaft that pushes/pulls the linkage. You should notice that both the draft control lever and the feedback turnbuckle linkage both can push the button, but they are independant of each other. So the idea is to adjust the turnbuckle so that the arms can move up a bit, then actuate the hydraulic valve, or the opposite. Hence the .28-.4" arm movement when the arms are up. Just make sure for any setting of the draft lever, once it stabilizes, the square metal part is not resting on the button unles you move the arms. With a heavy implement, there is also a valve that should bypass the fluid pressure with a hard jolt, if this is not working, it can create higher than normal pressure in the system, (the feedback can't react quickly enough).
I did not know about the draft mode lever, didn't notice it, but I will look and see if it exists and try to figure out how that is supposed to work, and if it does.
The key for me was my ears, I could hear the pump straining when things were not adjusted properly, if everything is setup, lubed, and set properly, there should be no noise or engine strain noticed unless there is a lot of force being placed on the arms, up or down. If you have a very heavy implement and you are bumping around a lot, I would lock the hydraulics with the knob under the seat to bypass the feedback mechanism to reduce the strain on the pump and bypass valve, just don't forget to open it again. Also, never tighten the speed valve lever too much, or the bypass will kick in! (then the fluid heats up, the pump strains, and something goes terribly wrong).
I hope this helps, and any corrections or further info is welcome.