Bush hog gear box lubrication

[TNhobbyfarmer]

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?

 

[ruffdog]

Stand the mower on end so the water at the bottom can run out the fill hole. The turkey baster will never get past the bottom bearing to get the nasty stuff at the bottom.

 

[pmsmechanic]

I ran corn head grease on my John Deere 506 for several seasons. Finally it just wouldn't stay in at all. So I took it apart and overhauled the gear box. It was a good thing i did that as the bottom bearing was very close to piling up. What happened was that the bottom bearing had rusted up because of condensation and eventually destroyed the bearing.

My experience has been that corn head oil will get you a few years but at some point in time you will need to rebuild the gear box. I had a mixture of oil and grease and I just added the corn head oil to it. If your seal is already leaking there won't be any water in the gear box. Water runs out first as the oil floats on top of the water.

 

[RoyKing]

The lower seals go then the bearing, rebuild before it dies

 

[AlbertC]

The lower seals go then the bearing, rebuild before it dies

Just curious. How difficult is it to rebuild the gearbox and any idea on the rough cost for parts. I have a bush hog 286.
Thanks

 

[RoyKing]

My bearings were fine and shafts were not grooved so about $40. for 3 seals, had doubles on the bottom and singles on the top.

 

[pmsmechanic]

This was a few years ago but I spent around $300. New blades and bolts were also installed.

The hardest part was getting the stump jumper off. It took serious discussion with a torch and a heavy hammer. I warmed up the splined fitting around the shaft and pounded on the stump jumper through the hole in the deck for the blade bolts. Once the stump jumper was off then it was just a simple matter of taking the gear box apart, ordering new parts and putting it all back together.

Because I had left it for so long the area for the seal was in rough shape. It was just barely able to be installed. I filled in the rough areas in the housing with JB-Weld and put a Speedy-Sleeve on the shaft. That has held the seal in place for several years now.

 

[TNhobbyfarmer]

My experience has been that corn head oil will get you a few years but at some point in time you will need to rebuild the gear box.

I'm not getting any younger, so a few years may be all I need. haha

 

[Sawyer Rob]

I've been running grease in one of my rotary cutters for more than 25 years...

You don't need to run any spl. grease in the gear box! NO matter what grease you put in it, it will settle down into the bearing and lube it just fine.

Buy cheap grease and put it in half tube at a time. Check it often to see that some is staying in there... I've never opened the box and found it dry, I just add a half tube before each big job.

SR

 

[SPYDERLK]

I've been running grease in one of my rotary cutters for more than 25 years...

You don't need to run any spl. grease in the gear box! NO matter what grease you put in it, it will settle down into the bearing and lube it just fine.

Buy cheap grease and put it in half tube at a time. Check it often to see that some is staying in there... I've never opened the box and found it dry, I just add a half tube before each big job.

SR

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.

 

[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.