Gear Box Contamination

[daBear]

Bought a Bush Hog RDTH60 finish mower earlier this year and it had been sitting in the open on the dealers lot for several months. Shortly after getting it home I noticed the gearbox oil looked like coffee with way too much cream in it. Not wanting to bother with taking it back I took the top off the gear box and removed the oil/water mix. I figured rain water got in through the filler plug on the top which has an air vent in it.

I store the finish mower outside, but with a 5 gallon plastic bucket, cut out for the drive shaft, over the gearbox. Problem is after two months the oil in the gearbox is contaminated again. Any ideas how the water is still getting in? Thanks.

PS. The only possibility I can think of is I did not remove all the oil when I change it as there are two small slits at the bottom of the gear box for oil to get into the very bottom and I did not get all of that out. You would have to turn the mower upside down or take the gearbox off to do that.

 

[john_bud]

2 possible things.

1) it could be from the moist air condensing in it. The box will breath and it can absorb a bit that way.
2) you could have left some it it.

 

[thatguy]

2 possible things.

1) it could be from the moist air condensing in it. The box will breath and it can absorb a bit that way.
2) you could have left some it it.

My LX4 seems to like the #1 answer.. last spring I check the gear box and it was almost empty.. After refilling and running it a while I checked the level and again and found that it was now quite milky.

Upon further inspection I found out that the pressure vent/breather valve (or whatever its called) was not working and when the pressure built up and must have forced the oil past the seals when it was almost empty and also caused the water to condense in the gear box after I refilled it... I bought a new valve and installed it after draining and refilling with fresh oil..

Even now the gear box is still a little milky looking, but not as bad as it was previously.. I may try to install another vent/valve in the fill hole (i found it was easier to just remove the top of the box to check the level and drain/refill.

I kept the mower under a canvas cover, so I dont think any rain was able to get into the gear box..

good luck

Brian

 

[daBear]

Yep, I think it is a little of both. But I don't like or want the milky looking gear oil in it. Think I will call Bush Hog and see what they have to say. It is not necessarily a BH problem, but I bet they have heard of it before.

 

[thatguy]

Yep, I think it is a little of both. But I don't like or want the milky looking gear oil in it. Think I will call Bush Hog and see what they have to say. It is not necessarily a BH problem, but I bet they have heard of it before.

I agree with you about not wanting the milky mixture, but I dont know how often I would need to change it to keep it un-milky...

BUT I bet most ppl only check the fluid level 1x/yr (if that often) and unless you take the top of the gear box off you would never see what color it is.. Based on this and that must cutters last decades, a little mikly probably isnt a huge problem..

Brian

 

[Skyco]

Youy might want to use marine grade gear lube if you can't figure out and stop the water entry- some of the marine grade lubes are supposedly specially formulated to tolerate water better and still function.

 

[Hooked_on_HP]

Remember, water is heavier than oil so most of what you couldn't get out of the bottom was water. As you ran the mower every thing got mixed up again. I have had to change the oil 2-3 times to get the water out when I have had this problem. Could you get a suction gun into the bottom to get everything out.
Bill

 

[daBear]

Remember, water is heavier than oil so most of what you couldn't get out of the bottom was water. As you ran the mower every thing got mixed up again. I have had to change the oil 2-3 times to get the water out when I have had this problem. Could you get a suction gun into the bottom to get everything out.
Bill

Don't know just how much contaminated oil was in the bottom, but this is the most likely scenario I can think of.

 

[john_bud]

Remember, water is heavier than oil so most of what you couldn't get out of the bottom was water. As you ran the mower every thing got mixed up again. I have had to change the oil 2-3 times to get the water out when I have had this problem. Could you get a suction gun into the bottom to get everything out.
Bill

Or flip the mower over with the FEL and hose it out with a couple cans of brake cleaner. Allow to air dry then refill.

jb