My obviouse answer to your question is never, as I need the coins for rebuilding these items, but the true answer is in your hands to firstly check the levels min weekly and secondly change the oil-s when you think its due for this task, oil is a small cost due to the low oil quantity usualy found within these areas, 2'000 hours is a fair amount of hours to stuff a load of BHP through a small amount of oil, take Excavators as an example, the F/Drives go through Hell of a time usualy in high speed track mode driving about for often little need with little to no oil service work done, when the oil drain-fill plugs get pulled the oil is usualy black ,smelly and possibly with sparkles, there might be a need to improve your service outlook if you are the owner, sadly J Deere equipment is not represented in the U.K. so I honestly have no idea about what happens within them, but the case with the small quantity of oil in I would refresh on a regular point posibly every other Engine oil change.
just my thoughts with no knowledge of JD iron tctractors
Am curious as to how important & how many of us keep the oil changed in the final drives like the machine manual says to do? For example my JD750 C has an inner and outer final drive that is supposed to be changed every 2000 hrs, the hour meter has 4600 on it now and we are changing it now. Would like some input on what others think.