dennis5150 said:
Can anyone explain what are low hours and what are high hours on a diesel tractor?
Clearly 800 hours would seem to be low and 3000 would seem to me to be high hours, and the type of work done within those hours are important, whether by a hobby farmer, a rental yard or a landscape contractor, as well as maintenance. Any help in correlating hours to say... miles on a car just to get a basseline idea would be helpful
Thanks
Dennis
This thread comes up often, it's an important facet to consider.
First off, a diesel engine should go about a Billion revolutions with excellent maintenance. Over the road haulers can and do go more, as they have lots of extra filtration and very large oil sumps.
Why did I list revolutions and not hours or miles? Most working or commercial equipment has hour meters that are based on revolutions at a specific rpm. Tractors have that based on the rated PTO speed. My Kubota is at 2600 rpms, but my old Ford is at 1515 rpms. That's why puttering around at low rpms puts hours on slower than watch hours. As Soundguy pointed out, that is exactly what you want in order to give maintenance when it is needed. A side note is that 5000 hours on the Kubota will be the same engine revolutions as 8580 hours on the Ford and is why people talk about the new high rev diesels wearing out faster. But how many of us will hit 5000 hours?
I have a lawn mower with an ignition switch triggered hour meter. My son at 2 years of age was sitting in the seat and flipped the key on. I noticed it two days later as it went from 50 to 100 hours. I don't think the engine needed an oil change at 100 hours, but the clock did. It didn't know that the engine hadn't been started since the 50 hour service. It's a cheap way of giving an indication of use, but not representative of how hard the use was. Counted revolutions does give an indication of how hard the use was.
On hours to car miles. It does not compare and don't even try to think about it. I have an hour meter on my truck. It went 54817 miles in 1369.7 hours or 40.0 miles per hour. Obviously, mostly on the freeway in 5th gear. If empty, that's about 10% throttle, if towing about 20% throttle. To compare, my tractor pulling a big box blade, a 2 bottom plow or the rotary cutter is at about 70% throttle and really working. Then again, the tractor's little engine is heavier than a 350 chev V8. Meaning the tractor is built to take the work and the passenger engine isn't.
If you use a Billion revolutions as the diesel engine life standard for this class of equipment, then you can determine how much life is left. Obviously, 3000 hours on my Kubota is going to leave less life than 3000 hours on the Ford. Assuming identical regular maintenance. As others noted - regular maintenance is much more of an indicator. New filters, clean castings, fresh grease on the zerks are all good things to see. Rusted filters, oil caked castings and busted off zerks are "bad, very bad".
jb
