Here is a quick one for anyone with experience. My swing gearcase oil always looks like it has water in it. Not so much water settled on the tip of the dipstick, but just milky oil. I have changed the oil at 2050 hrs and again at 2500 hrs. It could use it again at 2600 hrs. Im thinking condensation, but maybe a rain water leak? Ken
Could be hydraulic oil is getting past the swing motor seal and mixing with the gear oil.
I may have opposite problem with 01 Deere 370. Swing gear oil needs to be topped off every 50 or 60 hrs. No sign of leaks anywhere on machine. I don't know where its going.
If it was hydraulic mixing with the swing drive oil it wouldn't send the oil a milky colour IMO. I think the OP is correct, it's likely to be water.
your problem my be that the vent in the dip stick is plugged, where the handle curves is a dip stick and often the vent will plug with mud causing the condensation to build up in the gear box and put water in the oil.
ah ha! I'll look for that. Thanks
Fraser: you could be experiencing a phenomenom called "Archimedes screw effect". Have come across it once before with a swing box on large face shovel. Swing box level going down, but no external leak. It is caused usually by incorrect shaft seal alignment, I.E: seal is cocked in motor housing. Ken, i agree with DirectTech, check vent, & any other place water could enter. Another test, get a tube of water finding paste. I've used it before checking for water in bulk fuel storage tanks. It's like toothpaste, but green. Apply it to dip stick, and dip in fluid. if it still green, no water, I think it goes purple if any water contact. Been years since I used it but good product.
Another great idea. I checked that gearbox for a vent but can't find one. The dipstick is just a simple metal strip with a rubber stopper/metal cap on one end. No vent there. Can't find anything like a vent on the gearcase either.
I won't be of much help but I have the same problem - there was so much water in there that I couldn't have the infrared tests on the oil. In my case the vent on the dipstick was blocked with thread tape which makes me think the the previous owner had done that thinking the water was getting thru this way....anyway I changed the oil, removed the tape and I'm still looking for a clue on how water is getting in...
if the dipstick is OEM and the handle is curved then that is it, the handle is hollow and it is vented under the stopper i believe.
You need to replace the dipstick. There should be a new part number for the stick. This was a problem on many models and there was a design change.
I'll have another look. I think i will drop a coffee can on the dipstick to keep rain out for sure.
Low and behold, the dipstick handle is indeed hollow, with a vent hole just under the rubber stopper(That's a new one for me) . I tried to blow through it and got nothing so its blocked for sure. Will call strongco to ask about an update for it. Will try to clear it with a piece of wire. In the meantime, a new issue. I pulled the dipstick out in the middle of the day yesterday. It came out with a pop because of the pressure in the gearbox. Then oil erupted out of the tube and bubbled over for a while. Spilled a lot of oil. The gearbox was likely overfull. Will drain it to get it to the correct level and watch it. Thanks everyone for your help. Ken
Is it hyd oil coming out of the gearbox? If it is you need to pull the swing motor out and change the seal on the output shaft of the motor.
Today we drained about a litre out of the gearbox. Set the oil level exactly right. Will watch closely for the level to rise. Ordered new dipstick as well.
Update, installed that new dipstick and it is different than the original. The parts guy couldn't tell me whether the new one was an upgrade or not. I took a chance and ordered it, thinking i might end up with the same one as one i have. Fortunately, it is different, with a better vent design. The cap covers the top of the tube. Thanks to you guys for putting me onto this. Will have to watch the fluid level, to make sure it stays put. Ken