This was my first harvest with axialflow,so I hope this is good info. I have owned Gleaner all my life. Anyway back to your question! When i was shopping for used combines most of the things are the same. look for sharp augers+tubes,belts,bearings,clean grain+tailings elevators and sprockets. The feeder-house, engine, hydro are really no different to inspect than any other combine. The rotor and cage check for rock damage. One of the things I over looked was the sieve and shaker bushings cost around $1000 parts and labor.I think they usually need replaced 1500 to 2000 hours. Also I think there are 4 gearboxs that you need to pull dip sticks and inspect. It would be best if someone could phyically show you where these are located. I'm sure I've over looked somethings but this should be a good start. Good luck! Wolffman