Clutch Adjustment

   / Clutch Adjustment #1  
N

njensen

New member
Joined
Feb 3, 2010
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13
All,

I've been fighting with my clutch today, (Jinma 184 -TY-290 Motor), and I can't for the life of me figure out what's wrong, (perhaps the guy turning the wrench).

Anyway, what started my argument was minor grinding when I engage the PTO. This has been getting progressively worse, and it's time to get it fixed.

1. I started by removing the koyker loader pillar and viewing the distance between the clutch fingers and the TOB. The space was probably between .25 and .38" according to my eyball.

2. I attempted to suck out a bit of the distance, (aiming for 3/32 gap between fingers and TOB), by adjusting the clutch linkage.

3. This didn't help things, (but probably wasn't bad either). The PTO still grinds when engaging. At this point, it seemed clear to me that the clutch wasn't being pressed in far enough to completely throw out the PTO. I attempted to adjust the clutch safety switch and clutch pedal stop. There was not enough adjustment left in the pedal stop to make the PTO stop grinding when engaged.

4. At this point, I got a bit braver:

a. I shortened the clutch pedal adjustment so the actual clutch pedal lever would have more "throw."

b. This made the gap between the TOB and fingers much greater, -- not what I wanted -- but I should be able to fix that by adjusting the clutch

c. Then I adjusted the main clutch adjusters to bring the fingers back to within 3/32 of the TOB --now I had much more "thow" in the clutch pedal *and* the right finger/TOB gap

5. Keep in mind this was always very minor PTO grinding... Just needed a very slight amount of friction to stop the PTO gears and allow them to be meshed... I've never had a problem with the PTO spinning while I'm on the clutch. When I step on the clutch the PTO stops turning quickly even when there is nothing attached the shaft. Even with the *significant* additional amount of throw being applied, it doesn't seem like the grinding has gotten much better

6. For the life of me, I can't understand what may be causing the driven side of the PTO clutch to still be spinning with the fly wheel... It makes no sense...

If any of you have seen such a thing or have any ideas, I would be quite grateful.

-Nate
 
   / Clutch Adjustment
  • Thread Starter
#3  
Thanks for the input Tommy -- it is always valuable

In this case, I did a poor job of explaining... Let me add a #7 and #8 to the list above ;-)

7. I've also adjusted the PTO clutch to the point that it is throwing in/out at nearly the *same time* as the mains. (A bit less than .030" between the adjusting nut and and the plate).

8. I can see (at least I think so) that the PTO is being thown out... way out in my opinion.

Once the PTO gears have stopped turning, (forced to stop by grinding the PTO into gear), they never start turning, and the PTO can be put in and out of gear easily. However, as soon as I:

1. Take the PTO out of gear
2. Let off the clutch, and let the PTO gear system spin up
3. Press in the clutch again, (and even give the PTO gearing a second or two to wind down), it WILL grind again when I put it in.

I sure thought I had a firm understanding of this clutch, (read the book and plenty of forum / google posts). I must have a fundamental misunderstanding of what is going on... and I come right back to the question I initially had... What could be causing the driven side of the PTO to continue to spin with the fly wheel when it "appears" that the clutch is pulling it *way* out. Or better yet... Does anyone see my fundamental misunderstanding of the problem?

Thanks again
-Nate
 
   / Clutch Adjustment
  • Thread Starter
#4  
I've added a couple of pics with clutch disengaged and engaged, (respectively). Unless I am missing something, It appears to me that the PTO pressure plate is being thrown out between 1/8" and 3/16".... Far more than should be required.

Is it possible that the driven plate is not releasing from the flywheel cleanly? If so, what could possibly cause something like that?

-Nate
 

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   / Clutch Adjustment #5  
The 1st photo pretty much illustrates your problem, or at least the place you have to start. The spec distance between the clutch release finger tips and the throwout bearing face is only 2.5mm (+/- 0.5mm). That's less than 1/8", and your 1st photo clearly shows at least two fingers exceed that spec. Next - there is a spec for between/among the 3 fingers. When gapping the distance between the 3 fingers and the TOB face, there shouldn't be more than 0.1mm difference among the three. As pictured,, your TOB cannot possibly contact the 3 fingers simultaneously. This in turn causes incomplete separation of pressure plates and friction discs. Under those condtions, gears grind.

//greg//
 
   / Clutch Adjustment
  • Thread Starter
#6  
Greg,

I appreciate the observations... That pic sure does look bad. I do think this may show something a bit more sinister, (because I had actually very painstakingly and cautiously adjusted the release fingers as you describe). I don't think that photo is particularly clear either.

There seems to be a bit of 'play' in the release fingers, (i.e. the fingers don't seem to come back to the exact same resting spot each time). However, it does appear that they engage the cams/lobes which begin the throwout process at precisely the same time. That's not a statement I make lightly... I took off the spring on the clutch pedal so the TOB can slide easily. Then I backed two of the fingers off substantially. I let the TOB slide forward to where it would very lightly rest on the forward finger. I then brought up the other two fingers one at a time, (sliding the TOB up against fingers to test that they were actually 'firming up' at the same time.

Is it problematic that the fingers can be 'wiggled' in place? I'm not compressing the small finger return spring or anything like that... Just wiggling the entire finger mount. All in all, the machine only has 255 hours on it, and the clutch just isn't worn that bad.

The one thing that I would like to see is the PTO driven plate. I can see the main driven plate, and I can clearly see that the driven plate seems to behave like I would expect. I would be nice to observe the PTO plate in the same manner to see what if anything is causing it to remain engaged to the fly wheel when the PTO pressure plate is retracted.

Again, thanks all for the help, it is appreciated immensely.

-Nate
 
   / Clutch Adjustment #7  
   / Clutch Adjustment
  • Thread Starter
#8  
Gents,

Here's a couple of pics that are both in focus and don't have shadows across the release fingers...

I agree that there is too much thread showing on the PTO adjuster, and I can take a lot of that out, (which will of course require adjusting the mains as well to get the .030 - .040 between the adjusting nut and the pressure plate).

However, my initial concern was that I was not throwing out the PTO far enough... Clearly in this configuration that is not the case; the PTO is no doubt getting thrown out too far if there is such a thing.

Which brings me full circle to where I started... Why do the PTO gears continue to turn when the clutch is depressed. Assume that I do indeed have the fingers slightly off of the .1mm difference that is allowed. I will concede that is quite possible. Right now, the PTO pressure plate is being pulled back so far that it's hard for me to believe there is anything that could still be pressing the PTO driven plate into the flywheel.

Sorry if I sound obstinate, but I really am doing the best that I can to describe the scenario and what I see. Feel free to point out the error of my ways... I just want to get the PTO to stop grinding.

Thanks,
Nate
 

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   / Clutch Adjustment #9  
Nate,two stage clutchs can be a pain to get adjusted out correctly if your not experienced in doing it,and it's hard for me to see what you have from Texas,if you have followed the adjustment procedures and it's still grinding there may be another issue that you are not seeing,it may be better for you to take it to someone that has experience in two stage clutchs and adjusting them,I have seen the clutchs way out of adjustment do some really stange things

Tommy
Affordable Tractor Sales
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company
 
   / Clutch Adjustment
  • Thread Starter
#10  
Tommy,

That's an honest and fair response. I'll run through the process one more time and see if I have any more success. If I win, great. If I don't, then I will acquiesce and take the thing to a professional... Know anyone in ID that knows anything about Jinmas?

-Nate
 
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