Brush hog gearbox...oil or grease?

[MotorSeven]

My neighbor has an interesting theory on geabox's. He drains out the gear oil and stuffs the box full of grease. Say's that if a piece of wire wraps and cuts the seal the grease won't leak out. Is he nuts or is this an 'ole farmer trick of the trade? Or..... am i getting invited snipe hunting w/crocus sacks next !
RD

 

[mchasal]

While he may be right, I'd be concerned that the grease would get flung out of the gears by the centrifugal force and not flow back into them. So you'd basically end up with a box full of grease with a hole in the middle where all the gears are. I suppose if you really packed it tight with grease it would overcome that, but it still won't flow around. Part of oil's function is cooling and since you wouldn't be circulating the grease, it wouldn't have much cooling capacity.

Mike

 

[MMM]

Grease will keep wear particles in suspension instead of settling out of harms way. That being said, I've run a few with scored shafts that way for years. I change the grease by thinning it and draining every couple seasons or so, depending on use. To drain oil from new one isn't a good idea and is last resort when new seals won't work.

 

[Farmwithjunk]

I've stumbled on to a couple bush hogs (bought for re-sale at auctions) that were done that way. (for the same reason....seals out) I saw one GIANT glaring problem. Bush hog gear boxes are notorious for collecting water. (Condensation, pressure washers, ect..) When it comes time to change oil/grease, that heavy grease would be a real nightmare to get out. Oil comes out easy with a siphon gun.

I prefer to fix things right, and avoid making provisions for using while damaged or broken. JMHO, and worth exactly what you paid for it.

 

[RoyJackson]

You should use what ever the manual calls out...or contact Bush Hog and ask them.

My guess is you should use 90W Gear Oil.

 

[dsgsr]

Most of the old-time farmers in my area put grease in the gear box for the reason your neighbor stated.

David

 

[BattalionChief]

My "old farmer" neighbor has also done this on more than one ocasion.. With successful results.. More than one way to 'skin a cat.'

 

[Dex]

I had an old PHD that had a bad seal. Grease leaked out from a score in the shaft. Could not keep gear lube in so I packed it full of grease. It worked for awhile and then flew to peices. I have a new one now. Both have metits but I go with the gear lube when I can.

 

[MotorSeven]

Are the seals that hard to change? Never had to do one.....

 

[jgh]

20060618

I'm betting the Bush Hog crew will be aghast at the idea of non-liquid grease in their gear boxes (they are VERY responsive to email, write them). I'd 2nd the notion of using it only as a last resort where you had an old unit with bad seals that could be be repaired(?).

The point about cooling also sounds very important to me. If you look at where grease nipples are on machinery, you'll note that it is generally where the area is confined and heat is not as much of an issue, etc.

Not an engineer and feeling like I have almost tried to play one here (sorry PEs), so take my opinions for what they could be worth.

J