john deere hydraulic pump knock

   / john deere hydraulic pump knock #1  

Danscaper

Bronze Member
Joined
Apr 25, 2013
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68
Location
texas
Tractor
john deere
I have a new 3320 tracotor with ehydro. I noticed that the pump knocks a little bit at idle when the fluid is cold. Heard it in the rear of the tracot and chased it to the pump that hooks into flywheel of engine. Its not the motor. machine has 50 hours. The sound goes away after the fluid gets up to operating temperature. anyone notice this before.
 
   / john deere hydraulic pump knock #2  
I have what I believe to be the same problem on a Yanmar SC2400 with 30 hours. Mine is the opposite of yours , it makes the noise after it warms up. I noticed it when it had a couple of hours on it. The dealer came and listened to it when I wasn't home. Gave me an answer about a coupler and said keep an eye on it. With a five year warranty if its a problem I should know before that runs out, I hope. Is that Deer Yanmar powered ?
 
   / john deere hydraulic pump knock
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#3  
yes sir it has yanmar engine in it.
 
   / john deere hydraulic pump knock
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#4  
Doesn't seem to be normal. I just stopped over my cousins and started up his 3720 with 600 hours on it and it is quiet and smooth
 
   / john deere hydraulic pump knock #5  
I have a new 3320 tracotor with ehydro. I noticed that the pump knocks a little bit at idle when the fluid is cold. Heard it in the rear of the tracot and chased it to the pump that hooks into flywheel of engine. Its not the motor. machine has 50 hours. The sound goes away after the fluid gets up to operating temperature. anyone notice this before.

That would likely be the HST pump which is the eHydro transmission. They tend to be "whiney" in nature, anyway! :Big Grin: If the hyd fluid is cold or really thick you'll notice that the tractor won't respond very well going forward or in reverse. And your steering and 3pt will be sluggish, too.

You can always switch over to Lo-Vis JD20D hyd fluid.. although in Texas that might not be a good solution. Best to let the tractor warm up a minute or two.

AKfish
 
   / john deere hydraulic pump knock
  • Thread Starter
#6  
That would likely be the HST pump which is the eHydro transmission. They tend to be "whiney" in nature, anyway! :Big Grin: If the hyd fluid is cold or really thick you'll notice that the tractor won't respond very well going forward or in reverse. And your steering and 3pt will be sluggish, too.

You can always switch over to Lo-Vis JD20D hyd fluid.. although in Texas that might not be a good solution. Best to let the tractor warm up a minute or two.

AKfish
Thanks for the response sir. I have decided not to pursue this right now because it is not as evident with warm up. They will tell me to just monitor it anyway because I have warranty. What you say makes a lot of sense
 
   / john deere hydraulic pump knock
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#7  
Ok, so of course the service manager tells me the noise I hear is normal. Said he can fire up another tractor and it will have the same noise. Heres what I found howver, It is NOT coming from the pump like I thought. I was underneath the tractor while it was running and used a stethoscope on the pump and the engine and could not find the sound. I have narrowed it down to the TORSIONAL DAMPENER. With the tractor running, I hit the springs with a little shot of wd40 and the sound instantly went away. I guess I just have a noisy dampener. The dealer would never replace such a thing for a little sound so I guess I just will pass it off. Any input will be nice however from you guys. What would cause this dampener to be a little noisy. I poked around and found nothing loose. maybe spring noise. For those who don't know what im talking about, I added a couple pictures. It attaches the pump to the flywheel and looks like a clutch disc.
damp_zpsa74c72d6.jpg

desktop_zps0c03faa7.gif
 
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