- This topic has 9 replies, 3 voices, and was last updated 3 years, 1 month ago by
.
-
Posts
-
-
Lost my clutch on my Nortrac 254. Not sure if I ‘burned it up” or may need adjustments as the owners manual suggests that from time to time over use it may need ‘adustments” One moment I had a clutch and the next I didn’t. I was doing some pulling and pushing stumps…
In fact, here is what it says: ” Because of continual wear on the clutch parts during operation, there will eventually be clutch slippage or incomplete disengagement. Make the following adjustments as soon as you notice problems with the clutch.” I have never ‘felt’ the clutch slip so but it did become disengaged. No grinding, shimmying, shuddering, burning smell. Just disengagement…
The tractor was bought with a clutch that seemed to have a lot of ‘play’ in it. I never owned one with a dual clutch system so I figured the clutch that I bought was adequate for all the small stuff I do around my place; snow removal, wood hauling, brush hog, box grading… not much more than that.
I noticed on the ‘exploded view’ of the clutch there were parts that said: adjustment nut; adjustment rod, and adjustment fork. I get it that it may need adjustment but which way to I move those ‘adjustments”?
One of your other ‘posts’ mentioned a broken pin might be a problem also. Are they easy to replace or will I need some major mechanic help on this? I am very basic in my knowledge of mechanic work but the manual suggests that I may be able to do the adjustments myself. That ‘post’ didn’t say I couldn’t replace a broken pin so I”m thinking I may be able to do that myself. I get the idea of a ‘witness’ mark which is where I will start once I get the FEL unhooked. From there on I will need some direction.
Will I find an actual broken pin that I remove (2 pieces or more?} and just ‘slide in’ and replace a new one? I will need clarification on that when I get to it.
Am I on the right tract or way off base? If I need to get it hauled to have a professional do it I get that and am willing but not before I find out myself…I just may be able to pull this off…
Help if you can as soon as you can. Thanks
wmlroy
-
I would get another person to push the clutch pedal in and out as you look at the linkages, maybe you can see a lack of movement giving you a idea of there is a pin failure. As I remember people in the past were using split pins and inserting one inside the other to give them a little more metal to help prevent breakage. where are you located? As I think about this if , as you mentioned you had a lot of play maybe that pin was cracked giving the excess play and then completely gave out. When you figure this out I would make sure that the clutch play is correct to make sure wear is made normal.
-
Reading through your description it seems that you have an owners manual that shows the clutch diagram. Take a look at the manual I posted here: http://www.harnerfarm.net/Jinma/Jinma284.html (operation manual) and see if it is the same. Starting on page 22 it goes through the clutch adjusting procedure and is a pretty good explanation, but it took me actually looking at the clutch to completely wrap my head around it. Also on the same web page is a “Documentation” manual that has things worded a little differently starting on page 29. There is lots of other good info in there. Feel free to download a copy of anything on my site.
It seems you have a basic understanding but let’s go over clutch basics and define a few terms so we know what each other is saying.
The clutch is engaged when your foot is off the pedal and it is supposed to dis-engage when the pedal is fully depressed.
The clutch assembly is bolted to the flywheel and consist of the housing, springs, pressure plate and disc. The springs squeeze the disc between the pressure plate and the flywheel.
The disc is splined onto the input shaft to the transmission and quits turning when you dis-engage the clutch.
The pedal actuates a throwout bearing which then pushes against the clutch over-riding the built in spring pressure and moving the pressure plate away from the disc allowing it to stop spinning.
Our tractors with two stage clutches has an additional clutch disc that is connected to the PTO drive shaft. The transmission drive shaft is hollow and the PTO shaft goes through it to the PTO gears. The PTO disc is located next to the flywheel and there is a secondary pressure plate between the PTO and Trans discs (driven).
There is an external spring on the clutch pedal that keeps the pedal retracted and the throwout bearing away from the clutch so it does not spin needlessly.
(cont. in next post)
-
When you step on the clutch you first feel the resistance of the pedal spring, then as the throwout bearing begins to move the transmission pressure plate you will feel more resistance and if in gear the tractor should stop moving but the PTO would keep turning if in use. As you continue to press the pedal the transmission pressure plate “picks up” the PTO pressure plate moves it away from the flywheel and dis-engages the PTO driven disc stopping everything.
As the clutch discs wear they get thinner and the pressure plate can no longer squeeze then tightly enough to keep them spinning under load and they slip. Slipping is bad as it can “burn up” the fiber in the disc and actually heat damage the pressure plates.
On your dual stage clutch there are three things to adjust. The free travel of the pedal before the throwout bearing contacts the clutch, the travel of the transmission pressure plate and the travel of the PTO pressure plate. These things have to all be in sync for it to work properly.
Free travel of the pedal is adjusted externally by moving the clevis on the rod between the pedal and the bellcrank that turns the rod going into the bell housing. The clutch plate adjustments are done through the side ports on the bell housing, this is where the FEL brackets attach.
The first time I did adjustments I completely removed the FEL, but then I figured a way to jack up the left side of the FEL and just remove the left bracket. Either way works fine.
The pin that sometimes gets sheared is what connects the bellcrank to the shaft that goes into the bell housing and is external so you can easily see it. If this shears, the pedal and bell crank move but the shaft does not and when you step on the clutch nothing happens. This is opposite of the problem you described but cleaning the paint off of the end of that shaft and bellcrank and using a witness mark to confirm the integrity of the pin is a good idea.
There are three adjusting nuts for each pressure plate and the goal is to adjust them so they apply equal pressure all the way around the disc and they lift the pressure plate off of the disc evenly all the way around. Remember that if you are adjusting for normal wear of the disc you will be moving the pressure plate towards the flywheel to take up the extra space.
I think you can follow the procedures in the manual and documentation and do just fine. It is cramped work space and hard to see in there but is completely doable without putting it on the bench like the manual says. One hint I can give is to number each adjusting spot on each plate so that you can keep track of which one you need to work on next. Also a quick web search may turn up some videos about how to do this.
Let us know if you have questions and also the results of your efforts. It may help others in the future.
-
Will I see the same thing on the right side as I do on the left if I take off that cover plate? Is it necessary? I can see the clutch fine w/left side open. I can turn the clutch and observe 3 adjusting bolts. Is that correct?
I opened that cover plate to see the clutch and immediately got that ‘smell’ of burning…a lot of black residue laying in there. But, I don’t know if this is excessive or normal wear…
I figured that is not good…but will continue on. I checked the pedal linkage and didn’t see anything that might have sheared or undue metal wear. I may be looking at the wrong thing. All nuts seem to be tightened and in place. This all external–correct?
Probably a stupid question but….what are you using to determine the correct adjustment? A feeler gauge? Where do you get something that is 10mm or 25mm? And where do I measure from? The inside of the nut or the end of the plate? Trying to figure that out.
Indications suggest that if you don’t adjust evenly you may run into trouble…’I’m going to see if I can find something on YouTube…I’ll be back…
-
As to setting the gap on the clutch I would use a piece of hardwood( like oak)to what ever length you think you need and rip on table saw to the width you want and check with a good measuring device. If I remember right some have had issues with the springs failing in the pressure plate, I hope this is not the issue, that is a tractor split. Get your clearances and try adjusting the clutch first but I do not know if it will help I keep going back to you stating there was a lot of pedal travel, that would indicate the clutch was engaging the flywheel whereas if there was no pedal travel the clutch was slightly held off the flywheel. good luck
-
David and Piper,
My son who is an airline mechanic checked out my tractor today. He got farther than I did as I didn’t really know what I was looking for and looking at. He on the other hand has much experience reading ‘cut away’ diagrams and understands the ‘exploded parts view’ schematic also. After about an hour and some adjustments on the clutch pedal to the very max he figured out that the Main clutch disc assembly and the main pressure plate were non-functioning as the rivets on the disc were worn to the point that there was no material to ‘grab’ onto the pressure plate. He got the pedal adjusted as far as it could go and that closed the gap enough for the main pressure plate and the main clutch disc to meet tightly enough to actually move the tractor when we started the engine and put it in gear and let out the clutch. It actually moved which he said proved his observation that the main clutch disc assembly is fried, kaput, wobbly, good as dead. He figures there is probably enough clutch to drive it or back it onto a trailer and get it to a mechanic to have it replaced.
The Nortrac 254 is maybe a 20010- 2003 model…I am the 3rd owner so I figure that this would fall on me sometime. So I am now looking for an garage or mechanic within the Louisville, KY area or Southern Indiana area who works on Chinese tractors and willing to do the clutch replacement. Any ideas would be appreciated. I have a transport trailer so I can deliver. Distance isn’t a concern at this point. I am about equal distance to Indianapolis, Nashville, Cincinatti, St. Louis, Dayton, Ohio, Lexington, Ky. Surely there would be someone who could help.
I want to thank David and Piper for their guidance and expertise in the knowledge and willingness to take the time to share it. I am sure they have done it a ‘gazillion’ times. I have learned a lot about me tractor. I’m better for it.
-
to save you a few bucks take the loader off before taking it to a mech. I am not sure about this but I think Northern Tool might be able to be a parts source for you, also price a flywheel just in case yours in heat checked badly and turning it wont get it corrected. It is a shame that a simple adjustment was not done earlier by the other owners ,this could have been most likely avoided.
-
Will take that advice. Thank you. I know that Circle G also offers a complete clutch assembly. I will compare prices and let you guys know. I get most of my parts from Circle G. I know that Northern Tool sells Nortracs so I am assuming that they may know of service centers close to where I live. I will let you know how things turned out.
Did you ever receive those pictures I sent you? Were they helpful? If not, no matter now.
Thanks again David….appreciate you.
-
-
- You must be logged in to reply to this topic.