Help me learn more about the Deere 9400 combine and the crankshaft/harmonic balancer - pulley issue. I know this was only an issue with the small engine equipped combines. Are all of the 9400 small engines going to eventually fail? One guy who was a John Deere service tech told me it happened within minutes on a brand new just delivered Deere 9400. What causes this? Was there not enough crank sticking out of the engine? Too many pulleys hanging out there? Not large enough diameter? I am asking as I would consider buying a Deere 9400 combine. If the crank goes what does the repair cost? Thanks for the information.