Combines l2 main shaft bearing has spun 3 times

To start with i have seen very few machine shops do a good job of repairing shafts on combines. Giving them the benifit of doubt and saying the shaft was repaired ok, lets look a couple things. the bearing is a slight press fit on the shaft. it needs to be driven on with a bearing driver (something like a piece of pipe with smooth, square end). It also needs n680 green loc-tite, this isnt optional on combine bearings, it is required to perform as wanted.Be sure the bearing housing fits the bearing also, it cannot be sloppy or this willl cause problems. the nut that clamps the bearing and sheave to shaft needs n242 blue loc-tite and it needs to be TIGHT!!!! if that nut aint tight the bearing will spin. last but not least the shaft needs to be aligned to the engine......this needs to be done by someone that knows how with the right tools. hope this helps. vstk

I have found the cause, behind the spring tourque plate in the flywheel the shaft is to fit it tight. The shaft is worn and so is the flywheel. I will have to pull the flywheel, have the center hole turned. Have the shaft turned, then have a bushing made to match the two. This will eliminate the vibration that is causing the outer bearing to spin on the shaft. Think I am on the right trackIJ

Remachining the end of the PTO shaft and the flywheel is a waste of time. There is no bushing that goes in the flywheel. Sounds like your PTO shaft is out of alignment a long way if you are having shaft wear and failure that often. As VSTK mentioned in his post,you need a tight fit of bearing to shaft and also snug fit in housing.loctite is a must on shaft and nut(I use red on both.).You need to have shaft realigned by somebody that knows what they are doing as you may have to move PTO endplate up or down or move engine front to rear.Book spec. says within .030 runout. I shoot for half of that if possible.I would also purchase a new shaft instead of rebuilding.I can get that shaft from AandI depending on which engine and machine ser. n for $184-$300. Hope this helps, Hyper Harvest II

I have 77 m2 that has had main shaft built up 3x. first x i insalled a bronze bushing in fly wheel but a bearing was found to be much more durable. a 25mm bearing fits the end of shaft.Shaft end can be built up with bronze or weld and turned to a push fit. If your bearing supplier can get it -use a wide bore bearing

i have found the rear of pulley is worn into by the spinning bearing.. when this happens the inner hub wont press or hold the inner race against the shaft step..you need to build up the back of the pulley and also check the outer hub of pulley to see if it fits the shaft...if it is to short or the outer inner id is to tight it will not compress the inner race eventhough the nut is tight hope this helps

Not a bad idea to have stub on end of shaft but it was removed later on in the N days. Everytime we needed to align shaft the stub was deformed so we had to have flywheel turned out for bushing and stub on end of shaft built to match bushing. They provided us with a stub to stick in hollow end of shaft when it was time to align one. Anytime you are working on a drive that uses a large nut or bolt to secure you need to check protrusion of hub. It needs to stick out beyond end of shaft so you are double sure that nut or bolt is holding drives in compression against the inner race of support bearing. Easy way to check is to tighten things up well and then remove nut or bolt with washer to be sure washer is not bottoming against shoulder of shaft. large nuts and bolts do more than hold inner races of bearings from working into shaft when they go out. They also hold drive tight to make a very rigid solid assembly. One can't stress proper torque and this gap enough on this stuff for I'm sure it is the most common repeat expensive repairs that happen to combines. A couple hits on end of adjustable wrench just doesn't cut it. The nut you are working with should be in the 200 ft.lb. range. It worries me to have many of these shafts welded so I look for new or used. A snaped shaft will give you much bigger troubles. Be sure bearing will pivot in its holder free enough so it will self center when things are bolted up. If bearing can't self center you will get very short life. Should be no problem building up pulley as long as it is machined straight. If you have it machined straight you can use proper fitting machine washer between bearing and pulley to get your protrution beyond end of shaft. A l2 has a couple more set ups like this and that being corn head torque senser, traction drive torque senser if not a hydro, tapered hydro drive pulley on most brands of hydros, and rear cylinder varible. Rear cylinder varible will likely never bother or need to be checked for the pulley that drives unloader is screwed onto end of shaft and is tring to tighten things up everytime it is engaged. Anyway good luck with your project this time.