3-Point Hitch Pulsating 3pt. Hitch

[Gene Marks]

Pulsating 3 pt hitch
Thought someone would like to know. TC40DA 2006, 617 hrs. hitch started lowering about 1 in. then raising over and over again, when the engine was shut off the arms would drop to the ground in about 4 min. I took it back to where I bought it, which by the way is no longer a New Holland dealer after 89 years and had it repaired. What they found was; the cylinder walls were scored caused by the piston pivoting and the front and back of the piston was hitting the sides of the cylinder. They thought maybe it was being caused by something heavy being carried and the bouncing was butting to much strain on the piston. The heaviest thing I have is a 6ft brush cutter and I admit it does bounce when I travel with it. There suggestion was to chain it up when traveling and putting the control lever in the down position taking the weight off the arms. I spoke to another dealer痴 service manager and he said carrying the mower all the way up might help since the piston would be fully extended.
I contacted the New Holland area representative but he offered no suggestions to what was causing the problem or any preventive action that could be done on my part. He also offered no financial help since the dealer that repaired it was no loner a New Holland dealer and the tractor had 600 hrs on it. The repair cost was $1045, the cylinder was around $200 the rest was in O-rings, oil and filters and labor.

 

[rayikeo2]

No wonder they are not now a New Hollland Dealer. Looks like excessive labor charges for the job they did. I would find a new repair place next time.:confused2:

 

[jinman]

Gene, several people have reported similar problems lately. If your tractor was a gear tractor (TC40A) without the snazzy platform, you could have done that job yourself easily and saved a bundle. Working through a hole in the platform is a pain. Your dealer may have actually raised the operator platform and that is a labor intensive job.

 

[Gene Marks]

Yes Jim they did remove the platform, finders and rear tires. The New Holland representative told me he had heard of a couple of landscape contractors having the same problem. I ask if in another 600 hrs I could expect to have the same problem and he said possibly. Gene

 

[Jerry/MT]

Pulsating 3 pt hitch
Thought someone would like to know. TC40DA 2006, 617 hrs. hitch started lowering about 1 in. then raising over and over again, when the engine was shut off the arms would drop to the ground in about 4 min. I took it back to where I bought it, which by the way is no longer a New Holland dealer after 89 years and had it repaired. What they found was; the cylinder walls were scored caused by the piston pivoting and the front and back of the piston was hitting the sides of the cylinder. They thought maybe it was being caused by something heavy being carried and the bouncing was butting to much strain on the piston. The heaviest thing I have is a 6ft brush cutter and I admit it does bounce when I travel with it. There suggestion was to chain it up when traveling and putting the control lever in the down position taking the weight off the arms. I spoke to another dealer痴 service manager and he said carrying the mower all the way up might help since the piston would be fully extended.
I contacted the New Holland area representative but he offered no suggestions to what was causing the problem or any preventive action that could be done on my part. He also offered no financial help since the dealer that repaired it was no loner a New Holland dealer and the tractor had 600 hrs on it. The repair cost was $1045, the cylinder was around $200 the rest was in O-rings, oil and filters and labor.

Sorry to hear about this issue.

All that jiggling with a big load on the 3 pt causes pressure spikes that should cause a relief valve to open at the cylinder head and prevent damage to the cylinder and piston seals. Maybe your tractor doesn't have a relief valve at the head of the cylinder to deal with these types of impulse loads. I thought they were pretty much stanadard on modern three point hydraulic systems. Guess they are not. You'll have to either drive slower, leave the hog down, or chain it to the top link and put the lift lever down to prevent it from happening again.

 

[Soundguy]

spike loads are never good. that said a lil leakdown is pretty normal.. and on a heavy load at low idle, some leakdown and circuit regen will be seen.

my NH 7610s holding a 3000+# load at very low idle will drop and rais by 3/8 of an inch on a fairly repetive cycle.. and I have just under 1000 hrs on her.. at anything over idle it's no issue.

soundguy

 

[jinman]

Gene, I'm skeptical of what they told you at the dealership. My TC45D has 1700 hours and does not do this. It doesn't "hiccup" and it doesn't drop when the engine is shut off. I have done nothing but normal maintenance on my tractor since I bought it. Heck, I let the hydraulic oil go to 500 hours one time with only changing the filter because the oil was crystal clear and I just couldn't see changing it. I HAVE always used NH OEM filters everywhere on my tractor.

If you think about this, when you are transporting your mower, you aren't running it up and down, but leaving it in one spot. The 3PH piston should NOT be moving. If the seals are good, it stays right where you put it unless there is a shock load of over 3,600 lb. With this high a spike the 3PH cylinder has a special relief valve that will lift as Jerry/MT mentioned. New Hollands DO have this feature built into the lift cylinder. Anyway, scoring of the cylinder is created by the piston moving up and down while rubbing or with trash/debris scratching the cylinder. I think your lift should hold firm with a heavy load, or with a spike, pop the relief and drop suddenly. Scoring is from repeated up and down movement with something scratching the cylinder walls. I bet you can't tell me of any implement you have that causes the lift to move up-down-up-down-up-down. That's why I say this theory is "blowin' smoke."

There are several things that I would believe. One is the initial 50 hour service was not done and the tractor had trash that didn't get flushed out. The second is that the lift piston might have a design problem and cause scoring of the cylinder wall due to kicking out of position as it went up/down. The third possible reason is water in the hyd fluid in very cold areas could freeze and ice could do the scratching as it displaced the hyd. oil. Finally, the cylinder wall material could be too darn soft or not prepared properly at the factory. Any of these are "shots in the dark" at best. However, I think that's just as possible as an implement jumping up and down on a fixed position lift.

If you raised your lift and found it would not hiccup at lower heights and only hiccupped at the top, or a single spot, the bouncing wear theory might hold water. That's not how you said it did and you said it dropped all the way when the engine was shut off. I think your whole cylinder was scored and it wasn't at all related to anything you did wrong. That's my theory, and I'm stickin' to it.

 

[JC-jetro]

Totally agree with Jim's statements. Shock relief should kick in say I'm hanging 800 lbs 6 feet behind the 3 point lift arm. If you put a gauge and read the pressure with engine off you'll register quite a bit of pressure. Should you drive around on bumpy road/filed the pressure is magnified when you hit obstruction. The relif will go off to save your lift piston seal.

When i changed my lift piston seal notices that the piston actually is pretty lose in the cylinder and can slide in pretty easy. The lift seal (one or two) have double lip and the lip expand against the cylinder wall and seal tight. Junk in the oil and metallic debris sure can scratch the cylinder wall. I'm wondering if the ram rod pushing the piston is pushing it kind of sideways causing the scratches. I wonder if there is some misalignment there.

JC,

 

[JerryG]

Does this size of NH compact tractors have the traditional dog bone connecting rod to the lift piston?

 

[jinman]

Does this size of NH compact tractors have the traditional dog bone connecting rod to the lift piston?

Yes, this tractor is like all Ford/New Hollands I have ever seen with the rod having a ball that fits loosely into a socket on the back side of the piston. It is not attached to the piston like a rod in an engine.

EDIT: I just added a link to the diagram below. The rod is item #47.