We have a 2015 KX91-3S2 with approximately 850hrs. Today I was changing the final drive oil (Done yearly). The left side was perfect, very clean oil with nothing noticable in the oil. The right side was black with a lot of shinny metal, some very small flakes but generally like metal flake paint. I am guessing that one is failing and will need replaced? From my simple undertanding this gear oil side is seperate from everything else on my machine so I am thinking I dont need to panic there - is this correct? From my limited understanding I am better off replacing the entire final drive than attempting to tear it down and replace invidual parts, is this correct. I am thinking at this point everything is contaminated and trashed anyway? Is this correct or am I way off base? Thank you
Believe it or not it has a lot to do with the dexterity of the operator. Track wear has the same wear factors.
I replaced the entire final drive. Both of them. You are correct in saying that cavity you drained is separate from the hydraulic system. I think you could try to just rebuild the gear side, leaving the hydraulic side intact.
For a little extra cost and a heap of peace of mind, pulling down the hydraulic motor, lapping the slippers and lense plate, new bearings and seals, IMHO would be worth it and circumnavigates Murphy's law