4000 hours on an Onan QD

When I responded to your question on hours on another forum, I neglected to find out what year the 10kw Onan was. Reason I ask...on some of the earlier 10kw quiet diesels, there were two belts and when owners were replacing them, the recommendation was to put on the pulley kit to eliminate the two belts and instead have just one belt. When I had my onan 10kw serviced this past year, I found the new kit had been installed and was not necessary to upgrade with the kit. My unit had 2500 hrs on it and I had a new water pump, new belt, new brushes and new radiator installed (due to previous service center tightening drain plug too tight and cracking the plastic causing a hairline crack). So..be very careful with the torque if you have the coolant changed. Otherwise, my unit showed very little wear on the belt, water pump or brushes. Tech told me I could have gone many more hours before the service but like you, I wanted a baseline and figured since they had it out for the radiator, I would just go ahead and have it done. Tech also told me that upwards of 10,000 hrs on the Onan 10kw quiet diesel was not unusual before a possible overhaul and that he had seen a few with 15000 on them before rebuild. I really like the 10kw as it will give you 220V unlike the 7500. This allowed my unit to come with the stacked bosch 220V dyer which make laundry day very similar to home as far a time to wash goes. I would check for the fan kit though and see if it has been installed.