our son runs a 93 9600 and has been suffering numerous breakdowns this season. He has broken about 5 unloading auger shear pins, lost one bearing and now today has broken the front cross auger in the grain tank. All done since he first tightened and then also replaced the auger drive chain. He picked up a chain from the deere dealer that was supposed to be the correct number of links and it would not tighten up with the idler to his liking so he cut out one link. And the trouble begins.... any ideas, are these problems "linked" so to speak or is this coincedence and he has a larger problem. Our 97 9600 has not experienced any of these problems..... more hours and all.
Is the drive chain tensioned correctly? If the tensioner is to tight it puts stress on the other drive components.
If the chain is tensioned correctly, pull down on the chain between the vertical unloading drive sprocket and the rear drive sprocket - you should be able to pull and release the chain and the spring loaded tensioner should move up n down in it's travel slot - they can get worn and jammed.
check the timing of the vertical and horizontal augers - this can be done thru the front inspection cover of the horizontal auger - I believe the op. manual shows how the augers should be aligned.
Had one that kept breaking the shear bolts all the time even in barley but the previous owner had vertical auger problems, and after I replaced all the bad augers it kept breaking the bolts but mainly because the two hubs especially the one that spins on the shaft if the pin breaks was worn out and was putting too much erratic load on the other bub and bolt causing them to break without a real strain on them, Im in the process of changing both hubs, All other components have been ruled out already.