New clutch sticking, and not the normal simple fixes

[qualsite]

Just installed a new complete 8" clutch assembly in a Jinma 284. Now the clutch won't release.

I have the side inspection plate off, and the pressure plate is moving .125" with the clutch pedal fully depressed, and I can see space between the pressure plate and the main disc [fingers are adjusted at .095" to the new throw-out bearing, and PTO gap properly set]. I've "popped" it a number of times, and it will somewhat release if I block the tractor with the clutch fully engaged, but will still not fully release. I marked the edge of the disc with some paint, and forced it to "release" with the tractor blocked, and the disc is moving [paint is in a different spot, so it rotated between the pressure plates]. I cleaned the spline before assembly, and both disc spline and shaft spline were well coated with dry moly lube [no grease used]. Clutch tool was used for preliminary alignment when installing clutch, and inspection mirror used to watch shaft during reassembly to ensure splines were lined up when pulling split case back together. PTO was rotated to ensure splines properly lined up on PTO disc before reassembly. New pilot bearing was installed.

When I look at the gap between the disc and the pressure plate with the clutch fully disengaged at the 3 finger points, the gap is between different pressure plates [gap on left at one finger, and gap on right at other fingers], which could indicate the disc is tweaked. Since I know that it went in on the splines, has anyone heard of a pressure plate with the spline hub not straight, forcing the disc to "wobble" as it turns?

Before I waste another few days splitting the tractor to see what's going on in there, does anyone have any ideas why the clutch would be sticking or something else to try? Thanks

 

[jacques54]

Just risking a theory, one or both clutch disk on the wrong side, if possible.
Good luck.
Jacques.

 

[quicksandfarmer]

I had that exact same problem when I redid my clutch, I had put the diaphragm spring in backwards. And yes, no amount of adjustment made a difference!

 

[qualsite]

Thanks, but the clutch assembly was a new complete assembly, which I didn't take apart before installing. I now know that I should have, since if the main disc is warped from the factory, that would have been evident. Also, I know that the longer part of the splined hub was facing the correct direction on both discs, so there isn't any interference from the hubs that's causing this problem.

 

[qualsite]

When I got that new clutch assembly in, I was thinking that I should probably go ahead and tear it apart to inspect it before I installed it. Yes, that 30 minutes would probably have been well spent. I should have enough experience at my age to know that I shouldn't trust anything that is per-assembled when it's so hard to check after the fact.

 

[qualsite]

Just heard back from Keno Tractor's service guys. They played with a new Jinma clutch pack, and found that when it is turned vertically, like when you mount it on the flywheel, the Bellville spring washer can sometimes slip out of place, and when you bolt it down on the flywheel, it will lock that spring out of place. That would most likely cause a cocked pressure plate, and cause the clutch drag. I'll pull the tractor back apart and post the findings.

 

[quicksandfarmer]

That sucks. On the bright side, I found that when I had to re-do my clutch, it went much faster the second time -- two hours to get it split and four to get it back together. It's amazing what a difference it makes knowing what you need to do and having all of the tools and materials at hand.

 

[qualsite]

Got it pulled apart....yes, 2nd time to pull it apart was MUCH faster. Sure enough, the spring washer was a little out of place and cocking the pressure plate. I pulled the clutch pack off and disassembled it. Everything looked fine, no damage, and it reassembled fine. I actually tried to get the washer to slip when I was putting it back on the flywheel, and couldn't get it to slip at all, so it must take just the right angle and pressure on the fingers when you are installing it for it to slip out of position. Tomorrow we'll see how quick the tractor goes back together. This time, I'm making some 10mm alignment pins to slide the housings back together, and I made a better jack track to keep the floor jack lined up straight when the tail-end of the tractor gets pulled into the front half. I'm going to write a complete splitting and clutch procedure, and checking for the slipped washer will definitely be included.

 

[Affordable]

Did you use a clutch alignment tool, ? If you do not have the clutch discs aligned and you force the tractor back together it will also cause the problems you are having, that's why we include a free splined alignment tool with all of our clutch assemblies

Tommy
Affordable Tractor Sales
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