Rotary Cutter Two small holes in Bush Hog Filler plug

[bones66]

I致e got an old Bush Hog (brand). It痴 an older model 12. After a recent drain and change of lube I was looking at the filler plug and it has two small holes in it. I知 assuming the holes are a pressure release. The plug sets at a 45ｰ angle in the gear box so I assume I just put the holes towards the bottom. I guess the last time I changed the gear box oil I unknowingly put the holes facing upwards. I don稚 check the level very often as it doesn稚 leak. I was really surprised when I saw that milky looking oil. A lesson learned.

 

[pmsmechanic]

Yes the hole is just a vent so that when the gearbox gets warm the seals don't get pushed out from internal pressure.

I find too that most people over tighten those plugs way beyond what they need to be. It's only a place to add oil. There is nothing structural about a fill plug at all so just tight enough to keep it from falling out is good.

There my rant for the day.

 

[CoyPatton]

Yes the hole is just a vent so that when the gearbox gets warm the seals don't get pushed out from internal pressure.

I find too that most people over tighten those plugs way beyond what they need to be. It's only a place to add oil. There is nothing structural about a fill plug at all so just tight enough to keep it from falling out is good.

There my rant for the day.

I have seen a few folks over tighten these to the point they are difficult to remove in the future. I have seen one that was over tightened to the point of cracking the housing.
To the OP, it sounds like your mower sits outside or at least where it is exposed to weather. The plug and the housing are likely to be different typed of metals, you may want to use just a bit of anti-seize on the plug threads to prevent corrosion.

 

[bones66]

Never had a problem with corrosion or over tighten just that water that got into the gear box. I suppose I was surprised I never read anything about it in the manual. Yes I do allow it to sleep outside with the critters so I now will just make sure these holes are in the 6O団lock position.

 

[Rebeldad1]

replace the plug with a weatherproof one. no worries then.

 

[bones66]

To be truthful I壇 be concerned about blowing a seal. It痴 an old Bush Hog (mid 70痴) and it痴 still kicking without a minutes problem. So I guess those old Bush Hog engineers knew what they were doing. If I壇 been paying attention I壇 noticed those holes long ago.

 

[John0829]

I replace or install this style of vent on all my gear boxes

 

[bones66]

Don稚 know why my post have the foreign symbols?

 

[CoyPatton]

Don稚 know why my post have the foreign symbols?

It has to do with how TBN converts your contractions from your computer/phone. Not sure why, but it only seems to happen when we do things like ‘don’t and not if we do things like ‘do not’.

Computer programers!

 

[CoyPatton]

replace the plug with a weatherproof one. no worries then.

Continue to use a vented plug! It equalizes pressure which not using could cause issues with seals. To a much lesser extent, it allows a tiny bit of heat to escape, not sure if that will be a significant amount however.