Bush hog gear box lubrication

[Beltzington]

The gear box on my bush hog was leaking last summer. I partially filled it with gear oil but ran out of the oil and finished the refill with grease as a stop gap for the last use of the season. I intend to use corn head grease this season. What is your recommendation for emptying the gear box prior to adding the new grease? Turkey baster comes to mind. Any other thoughts?

Curious, why use grease instead of Gear oil? On my light and medium duty RC OEM recommends oil based on temp.

I bought mine used and when I serviced my gear box it was pretty nasty, I used a cheap manual oil syringe to suck all the old oil out, filled it up with diesel fuel and ran the cutter (no load) for about 5-minutes, sucked out the dirty fuel and refilled with cheap oil, mowed about six acres and then sucked that out and put high quality hydro oil. Sounds like a lot of work but really only takes about 15-minutes to drain and refill.

I did notice the gear box ran much cooler after servicing.

Good Luck!

 

[SPYDERLK]

Curious, why use grease instead of Gear oil? On my light and medium duty RC OEM recommends oil based on temp.

I bought mine used and when I serviced my gear box it was pretty nasty, I used a cheap manual oil syringe to suck all the old oil out, filled it up with diesel fuel and ran the cutter (no load) for about 5-minutes, sucked out the dirty fuel and refilled with cheap oil, mowed about six acres and then sucked that out and put high quality hydro oil. Sounds like a lot of work but really only takes about 15-minutes to drain and refill.

I did notice the gear box ran much cooler after servicing.

Good Luck!

If your gearbox is leaking (see OP) you lose the oil -- might be gone in an hour. An hour or 2 after that you have a very expensive time consuming rebuild. If you put grease in it stays. Put a little more in occasionally and youre probably good for your lifetime. Free money.

 

[Sawyer Rob]

Yeah. Standard NLGI 2 is fine as long as you cut some stumps and cinder blocks every few hours. Too much "lawn" mowing will slowly let the bearings dry out because the thicker grease gets pushed out and not shaken back in. Cornhead grease will slump back in on its own.

HUH?? I can and DO, cut for a whole day in grass,

and I've never found what you are saying to be true...

SR

 

[SARG]

Another tidbit I learned the hard way .... if your cutter is a cheap job it won't have a "vented" plug on it. You can plan on your seals being blown out the first of second season of usage.

 

[pmsmechanic]

Another tidbit I learned the hard way .... if your cutter is a cheap job it won't have a "vented" plug on it. You can plan on your seals being blown out the first of second season of usage.

I'd be willing to guess that the plug was removed to check the oil level and when it was reinstalled the re installer made sure the plug wasn't going to come out and get lost. As soon as that plug gets reinstalled "good and tight" it looses it's ability to vent.

 

[SPYDERLK]

HUH?? I can and DO, cut for a whole day in grass,

and I've never found what you are saying to be true...

SR

Yes, yours is probably quite full. I note that you said you put in another half tube before any major cutting. Also, maybe your grease is just a little lighter than some NLGI 2 grease I have used.

 

[pmsmechanic]

What's nice about corn head grease is that it turns to a liquid under pressure and then goes back to being a grease. So it can lubricate like oil but hang in like grease. It's not a lot more expensive than grease either.

 

[TNhobbyfarmer]

I recently learned that TSC carries 00 grease (I'm guessing equivalent to JD brand) @ $4.99/quart. By far cheapest I have found. I picked up a couple of quarts and will service the cutter prior to using this season.

 

[Sawyer Rob]

Yes, yours is probably quite full. I note that you said you put in another half tube before any major cutting. Also, maybe your grease is just a little lighter than some NLGI 2 grease I have used.

The grease I've used so far is, a mixed case of grease an old friend from Canada gave me, from the 1970's. What was left of a pail of grease my dad had around here from the 60's, and the CHEAPEST grease I can buy any place I can find it, some of it I got for 50 cents a tube, ALL of it works perfectly!

A half of a tube fills the box a quarter full or less, ANY cheep grease will work just fine, if you put in more grease, as the grease warms up, it just goes out the bottom.

Any grease that turns to liquid will go out the bottom fairly soon, I wouldn't use a grease like that, especially if it cost more than a buck a tube!!

SR

 

[Fallon]

Curious, why use grease instead of Gear oil? On my light and medium duty RC OEM recommends oil based on temp.

I bought mine used and when I serviced my gear box it was pretty nasty, I used a cheap manual oil syringe to suck all the old oil out, filled it up with diesel fuel and ran the cutter (no load) for about 5-minutes, sucked out the dirty fuel and refilled with cheap oil, mowed about six acres and then sucked that out and put high quality hydro oil. Sounds like a lot of work but really only takes about 15-minutes to drain and refill.

I did notice the gear box ran much cooler after servicing.

Good Luck!

When you pay $100 for an old beat to **** mower & new seals cost $70. I'm sure I could have found cheaper seals for my flail mower, but even if grease is way worse of a lube (its not) that gearbox will outlast the rest of the mower.