I have a Kubota tractor on my lot M7950 with 11,000 hours and runs like a top, never been apart (engine that is).
I have a client with an RTV900 that has over 10,000 hours of abusive use, never been apart.
I have a client that services reefer engines (mostly Kubota's) and he tells me they are seeing 25 to 35,000 hours on them before requiring rebuild. Gen set's in the mining industry that run 24/7 except when they are being serviced getting 20,000+ hours on them.
You will most likely wear the tractor out before you wear that Kubota diesel out.