Milky gear oil in JD LX6

[N80]

I've got a used JD LX-6 rotary cutter that I've had for over a year. It works perfectly and was in very good shape when I bought it. I bought it at a dealer and they said they had changed the gear oil and all that.

Well, at the end of last summer and a lot of mowing I checked the gear oil and noticed that 1) there was too much in the gear box and 2) it was very milky colored and it had not been used that day. So, I changed the gear oil using whatever JD recommends. Mowed a few more times and put it away.

Recently I got it out after sitting idle all winter and did some pretty heavy mowing. Checked the gear oil and it had the right amount but again was very milky. No signs of leaks under or on the mower.

I went ahead with a good solid day of mowing with no problems. Gear box felt a quite warm to the touch after hours of heavy use, but not hot by any means.

So what's up? I've always heard that water in the gear box does this. But where could water be coming from? I emptied the gear box last time I changed the oil. All plugs and seals seem to be in good shape. No leaks. It is stored outdoors though.

Any thoughts? I'll change the gear oil again, but do I need to do anything else?

And by the way, examining the gear oil I don't see any metal flecks, etc.

 

[DieselPower]

First, everytime you have checked it was it directly after using it? If you were checking it shortly after being used it may have been foamy oil you were looking at. Depending on how the gears are set up it might be more prone to introducing air into the oil causing foam.

A easy way to tell if it's foam or water is to put some in a clear container and let it set for a while. If it's foam it will clear up if it's water it will stay milky.

Not knowing exactly what this thing looks like it's kind of hard to make guess as to what's wrong. If you think it's water it has to be coming from somewhere. If it's humid it could be that the water is coming from condensation. You mentioned it is stored outdoors. Is it covered or is it exposed to the rain? If it get's rained on water could be finding it's way in past a seal or boot.

In either case a good high quality gear oil should be able to help with the problem. Try to use a waterproof gear oil and one with a high anti-foam additive package. If it is water from condensation the waterproof gear oil will allow you to just drain off the water. If it's rain water you need to either start covering it or repair the faulty seal or boot.

 

[N80]

Each time I checked it, it had been sitting for at least a day. It does not look foamy at all. It looks like beige milk. So since it isn't clearing up, it must be water.

It does sit out in the rain. The fill plug is on tight and does not leak. There is no leakage around the drain plug. There is a little vent cap on top of the gear box. I don't see how it could be a seal since there is no leakage of gear oil anywhere. Wouldn't it leak oil if a seal was bad enought to let water in? In any case, that does make me wonder if water is getting in through the little vent cap thingy.

Condensation could be an issue, it is very humid here, maybe even with the vent. Anyone have any idea how the little vent is configured? Is there a valve?

So, I guess my options are covering the mower (not a bad idea anyway), maybe replacing the vent, or getting waterproof gear oil. Where do you get that?

Just curious, what happens if I do nothing?

 

[DieselPower]

The breather probably isn't anything but a piece of pipe with a little cap on top. Most do not have a valve in them. I have spec'ed out some desiccate breather filters on industrial equipment before but I'm not sure if they make ones for exterior use. The ones I have ordered before are for use on interior hydraulic sump tanks and bulk oil fill tanks. I'll make a few calls tomorrow for you and see if any of the manufacturers I have ordered from make ones for use on outside equipment.

Just like in a engine water in your oil is not a good thing. It will cause rust and corrosionon the metal surfaces which leads to increased wear. A highly water resistant gear oil is 890 Vari-Purpose from TRC. If you check around with your local oil distributors you may be able to find a water resistant gear oil localy.

 

[N80]

Thanks, I'll take a look at that gear oil. I'll change the gear oil this weekend and keep the gear box covered for a while and see what happens. But, if its condensation, nothing is going to help. Seems like JD would have thought of that.

I think you are right about the little vent. It looks like its just a tube with a little cap on it, which would make condensation a potential issue.

The thing is hard to drain completely since the drain plug is also the fill level indicator. Last time I used a little bulb activated hand pump to get most of the oil out. I guess I may have left some water in there if it was in there before. I wonder if it would help to 'flush' out the old stuff with a little kerosene?

 

[teg]

Do you have a photo of the gear box? I'm "borrowing" an old Woods mower that had more water than grease in the gear box. The top cover was loose. I drained and soaked up all liquid. Then resealed the top cover. The oil & water mix did separated (after a couple of months). I would cut a 5 gal. bucket to cover the gear box to keep any more water from getting in, but I decided to store mine inside.

 

[Soundguy]

I'm sure mine are slightly different, however the 4 gear boxes on my JD 1517 all just use a fill plug/dipstick / breather cap combo.

As DP said.. the breather cap is just a crimped on piece of tin that clamps loosly onto the fill plug, that has a drilled head to allow vent to atmosphere so your expanding hot gear oil and vapor do not push seals out the gear box.

Souns like yours either had alot of water in it the first time and not all came out.. or yours is getting alot of condensation.

Last option is rain intrusion. Believe it or not.. even that little cap will let rain in under pressure. Ever see a cable tv line with a loop in it before it ran to your house.. that is a rain loop.. keeps hydrostatice surface pressure from pushing water up the line.

I think I'd add a dewatering agent to your current gea oil.. like transtune made by seafoam..fill the box nearly full.. the 1 pt TT can should pretty much do that with your old gear oil in there anyway... spin the mower over for a minute to mix, then drain the box.. use a battery water bulb to suck the last bit of gear oil out.. then refill with good quality fresh gear oil as DP reccomend.

The transtune carires water out in soloution.. not suspension..

water emulsion is not good for the bearings..

Soundguy

Thanks, I'll take a look at that gear oil. I'll change the gear oil this weekend and keep the gear box covered for a while and see what happens. But, if its condensation, nothing is going to help. Seems like JD would have thought of that.

I think you are right about the little vent. It looks like its just a tube with a little cap on it, which would make condensation a potential issue.

The thing is hard to drain completely since the drain plug is also the fill level indicator. Last time I used a little bulb activated hand pump to get most of the oil out. I guess I may have left some water in there if it was in there before. I wonder if it would help to 'flush' out the old stuff with a little kerosene?

 

[NoMo]

My LX6 sits outside (uncovered) and has no sign of water in the oil.

If the picture attached properly, you can see my cutter is slightly over-filled and blows a little oil out the vent when running. But it'd be tough for water to infiltrate the gearbox when everything is properly installed/sealed.

 

[DieselPower]

Well isn't that a cute little gear box.

Here's a thought for a water cover you could install. Go to the local 5 and dime store and buy a little 1/4 cup cooking measuring cup with a handle. Drill a hole in the handle, remove one of the top mounting bolts and reinstall it through the hole you drilled in the handle. You now have a rain cap for the breather. You could also run a good bead of silicone around the top access plate to ensure it is sealed good.

 

[jimgerken]

It is surely getting water in it by what you describe. First, you must figure out how to drain it completely. Tilt the mower, hoist it up, remove the gearbox, whatever you have to do. Get it all out. Then find the water entrance. From the photo, I would suspect the flat plate cover has a gasket under it. Replace it and RTV it in place. RTV or pipe dope all plugs and any other entrances. Check the shaft seals. They can't cost much. Then refill it with gear oil , run it an hour, and drain it again COMPLETLY. There may still be traces of water in it. Repeat again untill it is only oil. Next, find a lean-to to store it under, or throw a pail over it with a big rock to hold the pail down. Even a canvas could help a lot. If you don't deal with it, the water will cause rust and then the wear will accelerate wildly. Soon it will be REAL noisey when it runs. Good luck.