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I have a 1979 L-2 non-hydro and the right hand pivot drive belt tightens on its own. It eventually breaks and piles up everything. Even with the updated torque sensor it still does it. I have to watch the cylinder rpm gauge and as soon as it goes up I have to stop the combine and loosen the belt off, otherwise everything will pile up again. It is definitely worse at low cylinder speeds, such as in a heavy canola crop. Any ideas??
 

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I'm sure that the cams were polished or replaced when apart so they should be OK. The grease zirk on outside of sheave greases the sliding hub and I imagine it was greased well when put together. What you likely have is the sliding sheave it binding on hub. You will need to take apart again to emery cloth the hub to get smooth and then go into the sheave with a cylinder hone. We use a hone that is made to break the glaze on a cylinder wall. We'll hone it enough so a .006 to .008" feeler ribbon will fit between hub and sheave. This will give enough clearance to prevent the two from binding up when the temp gets just right. Good luck
 

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the sheave and hub and cams and spring were all replaced with an updated version.Still the belt tightened. We changed some bushings on the left side of the main clutch shaft (variable speed traction drive). This helped but shortly after in the same season the belt tightened up again. we also have trouble with the traction drive belt slipping and wondered if the two problems were related (same shaft).
 

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This problem has usually started after replacing hub with new style when old spline gave up. Normally the sliding sheave was not replaced. Anyway it seemed that clearance was just not enough to prevent binding. Once a little heat started building in one or the other piece it started to bind. The torque senser would snug belt a little more with each slug until idler broke off, belt flipped, or worse yet snaped off the shaft. I don't believe anything on left side could affect right side. I would get the torque senser checked out for traction drive. It has a double cam which should snug the belt no matter if it is engine pull or going down a hill type pull. If cams are good hear and spring hasn't lost to much length I would be sure the sliding hub is not to loose on hub. Also be sure you have enough gap between sheeves with drive slowed all the way up. I believe they call for .200" hear. Good luck
 

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I had this happen and found the bearing was bad behind the adjustable sheave. This let the sheave get out of alignment and made the belt get hot and finally roll over and break. Make sure after you put new bearings in that the sliding sheave is greased and moves easily. Good luck
 
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