I had a 9650W. By 1700 hours I had replaced all 5 unloading augers, the unload tube, lined under the bin augers with stainless steel, and replaced the loading auger twice. It wasn't rot, as the combine was sheded when not in use.
These machines unload pretty slow unless you speed up the augers. In corn with a grain cart, about 1/3 of the header time was required for unload time. 1700 separator hours is over 500 hours of unload time.