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Discussion Starter #1 (Edited)
Now that my motor purrs like a tiger I need to fix the clutch. I must be losing pressure as under load at higher RPM it will jump out of gear. I can downshift to 2nd or 3rd and lower the RPMs and then it will engage again and sometimes I can upshift to a higher gear again.
I was trying to plow a field and 3rd gear pulling a 4 bottom plow was the best I could get and it is mostly short lived.

Any ideas on the best approach would be appreciated

Is the 4230 similar to the 4630. I found a youtube video that seemed pretty good
JD 4630/4430 PTO valve body repair - YouTube
 

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What trans does your tractor have? Please elaborate on your term "jump out of gear". Traction clutch should engaged or disengaged. Yes 4630 & 4230 traction clutches are very similar.
 

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Discussion Starter #3
Transmission type and "Jumps out of gear

I believe it is called a "Power Shift" 8 forward 4 reverse.
If I am in 4th or 5th gear for instance and I am under load the tractor will appear to drop out of gear and will come to a stop. I have to push in the clutch and reduce the rpm or downshift or both and then let out the clutch and then it will move again.
Once moving and as long as the rpm isn't too high I can upshift again and it will go for a while until it happens again. while pulling my 4-bottom plow I was having a hard time keeping it engaged in 3rd gear. plowing a 40 acre field in second gear sucks

It's like I am losing the hydraulic pressure to keep the clutch engaged. It has done it, but only once, to the PTO when I was mowing some very thick alfalfa/grass but I think that was more due to being low on hydraulic fluid as this beast used to leak so badly that I used more hydraulic fluid than diesel fuel.
 

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There may have a problem with the engine clutch(#9 - torsional dampener) slipping. This is a dry clutch, which is always engaged. If oil(engine or trans) is intruded to the clutch face, it will slip, slowing or stopping machine travel. If the torsional dampener is slipping from oil introduction, you'll need to determine where the oil is coming from(engine oil seal, or trans. input shaft seal) and replace/repair it.

A gauge will need to be installed on the Trans Pressure port to determine if it's a mechanical, or hydraulic problem. If the clutch operating pressure is low, the clutch pack(C1/C2) is possibly slipping. If the operating pressure is at specs, the problem may be with the torsional dampener. Either way, the tractor will need to be split at the engine/clutch housing for repair.

Note: There are a few things that will cause the operating pressure to be lower than specs. Hydraulic pressure low, C1/C2 clutch piston sealing ring blown, or clutch operating valve gasket blown. Whatever is causing the low operating pressure will need to be determined for proper repair.

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Discussion Starter #6
Things I've already done

I have checked to transmission shift side through all of the ports and the readings are where they are supposed to be.

I have also checked the pressure reading on the clutch valve ports and they were where they needed to be.

Movement of the tractor under no load or when pulling the baler or hydro-swing is pretty normal, although if I use 5th or 6th gear it will even under that small load sometimes do the same thing.

I have changed both filters and checked and cleaned the screen.

I was wondering if some of the seals/o-rings inside might be leaking fluid?
 

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I have checked to transmission shift side through all of the ports and the readings are where they are supposed to be.

I have also checked the pressure reading on the clutch valve ports and they were where they needed to be.

Movement of the tractor under no load or when pulling the baler or hydro-swing is pretty normal, although if I use 5th or 6th gear it will even under that small load sometimes do the same thing.

I have changed both filters and checked and cleaned the screen.

I was wondering if some of the seals/o-rings inside might be leaking fluid?
If the pressure readings are where they need to be(as you state), there is no leak(s)/significant leak(s).

Can you stop the movement of the tractor by applying the brakes?? If so, which gear speed is effected??
 

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Discussion Starter #8
which gears are affected

f the pressure readings are where they need to be(as you state), there is no leak(s)/significant leak(s).

I'm going to check those on the clutch valve again to make sure.

Can you stop the movement of the tractor by applying the brakes?? If so, which gear speed is effected??

I don't need to hit the brakes it comes to a stop by itself. while pulling the plow in 4th gear I was running along and then the tractor just comes to a stop. All gears 4th and above have the same issue it that they will do that. 3rd has done it while plowing but it has to be pulling pretty hard or if my rpms are up near the 1800 range
2nd and below don't do it
 

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Discussion Starter #9
another thing to note

I do have a small hole, smaller in diameter than a ballpoint pen, in the transmission casing. It almost looks like something shot out through it as the metal around the edge is splayed outward. I do get some hydraulic fluid that will drip from there and from what I understand the inside of the casing should be fluid free.

The more I type the more foreboding I feel about having a tractor-splitting operation in my future.

My MF1155 is already ahead in line as the clutch linkage or clutch assembly won't allow me to shift into any gear but the one it's stuck in and the clutch never fully disengages but the tractor can be held stationary with the brakes.
 

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I agree the torsional damper clutch disk is most likely slipping since the transmission pressures are good. Most likely oil is leaking on it to make it slip. I recommend while you have it split to also disassemble and inspect/reseal c1, c2, and pto clutch packs. And replace rear main crankshaft seal.
 
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