JD 4300 hits a brick wall????

   / JD 4300 hits a brick wall???? #21  
Agvg said:
Loosing oil pressure in the transmission might be an issue, the behavior of the pedal excludes front axle faults by my logic, suppose you have a test outlet so it might be an idea to put a manometer there and have it so you can read it under normal use, to see variations and see what goes on when it have the problem.
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If you load up the front axle which puts the drive line in a bind it can make the pedal rise up. If as jd110 mentions the possibility of a broken tooth jamming the gears would lead to a sudden spike in the hydrostatic transmission pressure and could cause the pedal to rise up. The pedals would not react this way on the Ehydro transmissions which are electrically controlled but could on the 4300 which has mechanical linkage to operate the transmission.
 
   / JD 4300 hits a brick wall???? #22  
jd110 said:
I would recommend draining the oil in front axle and transmission. Remove the sump screen and check for any debris in the oil and/or screen. Use a long flexible magnet to probe into the transmission and axle to see if there are any loose pieces. It sounds to me as if there is possibly a broken tooth floating around in the system ad occasionally getting caught between two gears or between a gear and the housing. If so, you are in a real danger of having a catastrophic failure. If no loose parts are found floating around I am not sure what is going on. Keep us posted on what you figure out.
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jenkinsph said:
If you load up the front axle which puts the drive line in a bind it can make the pedal rise up. If as jd110 mentions the possibility of a broken tooth jamming the gears would lead to a sudden spike in the hydrostatic transmission pressure and could cause the pedal to rise up. The pedals would not react this way on the Ehydro transmissions which are electrically controlled but could on the 4300 which has mechanical linkage to operate the transmission.
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Yes! I think its a bearing or gear problem in the front end.
larry
 
   / JD 4300 hits a brick wall???? #23  
Then the oil should give a hint, a bearing so bad it its giving such behaviour would almost certain make noise.
 
   / JD 4300 hits a brick wall????
  • Thread Starter
#24  
You guys are giving me a lot to do when I get back to the tractor next week.....😁

I appreciate the advice and will go through a checklist gathered from your suggestions and see what comes out the other end.
 
   / JD 4300 hits a brick wall???? #25  
Agvg said:
Then the oil should give a hint, a bearing so bad it its giving such behaviour would almost certain make noise.
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Oil should show it. -- But in a lo speed bearing tractor noise often obscures the sounds until they are "felt". I have experienced failure of the bearing cage in a Kub front hub bearing. The balls jammed. Similar symptoms to the OP.
 
   / JD 4300 hits a brick wall???? #26  
But here there is a brutal stop of the whole tractor as I understands it, might be a hydraulic valve blocking for pressure and the noise can be a security valve blows?
 
   / JD 4300 hits a brick wall???? #27  
Rear differential picking up a loose bolt or something could make noise, an cheap USB inspection cam might be able to see inside the transmission, if this are mechanical damage it should be easy to see if the cam can get there.
 
   / JD 4300 hits a brick wall????
  • Thread Starter
#28  
I performed a full hydro change this past week and found the fluid to be putrid. I changed the filter and all the fluids. While doing the change I took out the sump screen and discovered it was damaged. It also had a lot of metal filings in it. I took a magnet and scoped the interior of the transmission housing and pulled out a C clip. It appears that something came off and was banging around in there causing the damage to the sump screen. I got a new one and put it all back together. Whatever was banging around appears to be ground up. **** if I know what it was cause everything is working as it should. The only thing that I do not use is the mid PTO. It could be that gear that came off. I will have to try it when I get there on Friday.

I ran it pretty hard for a few days and all seems fine. Thanks to all who chimed in. And if you have any other thought feel free to let me know what they are.
 
   / JD 4300 hits a brick wall???? #29  
Scary. What are the hrs on this tractor?
 
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