Water in Gear Box-Part II

[N80]

You guys might remember a recent post by me regarding the gear oil in my JD LX6 mower always being a milky color. I had assumed it was water.

So, I flushed the gear box out. Pulled the top off of it and cleaned it all out with kerosene. Cleaned out the vent tube (ball vlave). Resealed it all back up with new gasket for the top. Made a bucket to fit on top to keep rain out.

There are no oil leaks anywhere.

So its been a few weeks and I've probably run the cutter a total of two hours. Ran it for about an 1/2 hour Saturady afternoon. Sunday morning I checked the gear oil and once again it looks like coffee with a lot of milk in it. There are still no leaks and the bucket has not been off of it since I put it on there. Not a drop of rain has hit that gearbox.

So I'm stumped. I'm sure that the gear oil gets frothy when you run it. But I'd think 16 hours of sitting still would be long enough to let it settle back down. But I'm starting to think that there is no water in this thing. Next week I'll check it after it has been sitting for seven days to see what the oil looks like.

In any case, I've done all that I can and I'll just have to run it this way. I guess I'll change gear oil more often. It is about a 10 minute job so no big deal.

 

[jdbower]

I remember reading once that it takes shockingly little water to create a milky emulsion in oil and that frequently it requires 2-3 oil changes to clean up completely - but this was based off a big internal combustion engine where the kerosene phase is probably not recommended unless your fire insurance is paid up

It's also a little known fact that WD-40 is not actually a lubricant, but a water displacement chemical. Spritzing the inside liberally may provide slightly better results than kerosene.

The no oil leaks part is a very good thing, as long as the oil still lubricates I'm guessing you'll be fine with just more frequent changes if the issue remains. Best of luck!

 

[N80]

I remember reading once that it takes shockingly little water to create a milky emulsion in oil

I've heard that too. And someone speculated that this could be from condensation inside the gear box. But if it is , I have no idea what to do about that.

It's also a little known fact that WD-40 is not actually a lubricant, but a water displacement chemical.

When I say I cleaned it out, I really did. And I did use some WD-40 at the end. When I was done cleaning there was no oil or fluid of any type left in that gear box!

 

[Farmerford]

I have two "Bush Hog" brand rotary cutters and the original gear oil was (and still is) a milky brown color after the mower runs a few minutes. A few years ago I put sight glasses in the "level check" holes so that I would not have to take the pipe plug out to check it, and I can see through the sight glass that the oil stays milky all the time. I think it is air entrapped in the oil because of the strong stirring action from the main (lower) gear that is fuly immersed in oil. That could make the stirring of the oil much more violent than, say, in a rear axle where larger gear is vertical and only the smaller pinion may be immersed in the oil.

 

[jdbower]

When I say I cleaned it out, I really did.

I shoulda known you would be that through, George!

 

[N80]

I think it is air entrapped in the oil because of the strong stirring action from the main (lower) gear that is fuly immersed in oil. That could make the stirring of the oil much more violent than, say, in a rear axle where larger gear is vertical and only the smaller pinion may be immersed in the oil.

That was what my farmer friend said....but he was not real interested in my gear box problems. And when filled to the proper level the pinion gear top edge is just a little above the oil level so I do bet that a lot of air gets stirred into that oil. The word 'emulsion' comes to mind.

 

[N80]

I shoulda known you would be that through, George!

Well, I did forget one thing. I meant to document the whole procedure with my Nikon. But forgot. I hate it when real life intrudes on my photography!

 

[Farmwithjunk]

I remember reading once that it takes shockingly little water to create a milky emulsion in oil and that frequently it requires 2-3 oil changes to clean up completely - but this was based off a big internal combustion engine where the kerosene phase is probably not recommended unless your fire insurance is paid up

It's also a little known fact that WD-40 is not actually a lubricant, but a water displacement chemical. Spritzing the inside liberally may provide slightly better results than kerosene.

The no oil leaks part is a very good thing, as long as the oil still lubricates I'm guessing you'll be fine with just more frequent changes if the issue remains. Best of luck!

If I'm remembering correctly (forgive me for I am old) WD40 is an ether based product, more a solvent than a lubricant.

Kerosene and or diesel fuel is a good cleaning agent as well as possessing some lubricating qualities. I've flushed the hydraulic sumps of dozens of tractors with diesel fuel. With diesel, a little left behind after cleaning won't do any significant damage.

 

[Farmwithjunk]

I have two "Bush Hog" brand rotary cutters and the original gear oil was (and still is) a milky brown color after the mower runs a few minutes. A few years ago I put sight glasses in the "level check" holes so that I would not have to take the pipe plug out to check it, and I can see through the sight glass that the oil stays milky all the time. I think it is air entrapped in the oil because of the strong stirring action from the main (lower) gear that is fuly immersed in oil. That could make the stirring of the oil much more violent than, say, in a rear axle where larger gear is vertical and only the smaller pinion may be immersed in the oil.

Last spring I bought a new Bush Hog 286 cutter. No matter how many folks before me CLAIMED to have checked the oil in the gearbox, I'm the one who has to live with the outcome. So.... I checked it AGAIN before it made the first cut. The oil was a tan color, but not "milky" when absolutely new.

The gearbox on a bush hog will get hot in hard service. I'd think with a vented gearbox you MIGHT get a small amount of condensation, which in time may muddy up the oil.

 

[DieselPower]

WD-40 is not ether, never has been.

Without being able to see what the gear oil looks like it's hard to say if it's water contamination or foam. If it's foam then you should be able to see very small air bubles traped in the oil.

In any case it sounds like you need a good waterproof gear oil with a good anti-foam additive package.