Now that we have our excavator up and functioning. We noticed a couple "minor" things. The first thing is it just seems, compared to our larger ex200, that the controls are all "sensitive." What I mean is that you can get jerkiness if you move too quickly. Yes, I know there is a point where that is an expectation, but it just seems "more"compared to the larger machine. That isn't a huge deal, as it is controlled, with just finer movements on the sticks. What does seem odd is the play in the swing function. When you swing the machine, and then stop, it still swings another inch or three. Similarly, it might swing a little bit when doing another function that might put a little "torque" in lateral direction. Some things that have been done recently. We drained the swing motor gear oil, it was fine as far as debris. Its been refilled. I will say that there is something magical about that reservoir. First, we drained hardly any oil out. The spec claims it has a capacity of maybe 3-5 gallons. We easily put 10+ gallons in before anything read on the dipstick. I'm not sure where it all goes, but there are not leaks...so either the capacity is referring to some reserve area and the rest had completely leaked out over time or something, or I don't know what, but it seems a good bit of information to provide given the symptom. WITH that said, we actually had the EXACT same thing on the larger machine EX200. Nothing drained out and we refilled it with at least 10+ gallons, but that ones works fine. So any initial thoughts?
Find (2) screenshots below from EX120-2 Operators manual re: swing gear box maintenance Capacity chart shows only 1.1 gallons. If you put in more than 10 gallons, the swing gear box lower pinion seal must be leaking and the excess oil is sitting in the swing bearing ring gear cavity. The swing bearing ring gear cavity is to have approx 1-1/2 inches of grease only. Remove the diamond shape cover between the 2 boom cylinders and check what‘s actually in the swing bearing gear cavity. .
I'll check this Monday. This is a very naive comment, but is the seal replaced by "simply" undoing all the bolts at the bottom holding the swing gear motor?
See screenshot of parts breakdown below. Remove bolts #127. Remove bolts #17, the seal and seal housing slips down over the pinion and wear sleeve. I suggest to flush the bearings and gear box lower housing with diesel fuel. Spin the housing and listen for any rumbling / skipping sounds. This will give an indication of the bearings internal condition without pressing the bearings from the pinion. .