After waiting for the wildflowers to seed out, I’ve started shredding pasture around the house. Did maybe 8 acres and the shredder was rather noisy. I checked the gearbox, with the thought of fresh gear oil, and found it had no gear oil. Put oil back in it, and the noise has abated. The problem is that the oil must have leaked out through a seal at the bottom of the gearbox. Well…that’s just great. Other than a new gearbox, I’m open to suggestions. Heavier gear oil maybe? Buy a new shredder and don’t tell the wife? Check the oil level often, I suppose, and hope for the best, is the present plan.

Fill it full of John Deere cornhead grease and be done with it. Filled my good batwing with it this year. It is a lower viscosity grease that somewhat liquifies when warm but thickens up when it cools and doesnt leak thru a seal near as fast. It still may leak some, but not like oil. You can re-seal the box so the gear oil wont leak out, but it can be a pain and usually requires lots of torching and heating to get the blades and stump jumper off. Hopefully you shut it down soon enough where your didnt roast the bearings.


Now, i will say this. I do have a different old beat to heck shredder that i use on thick and rough stuff so i dont tear up my good mower. I have it full of standard red high temp grease all the way to the top, and i havnt had any issues out of that either, but it usually runs for short intervals.

Thanks much!

Been running a 7 ft howse on mystic red for about 4 years now no problems just took the top plug out and pumped a couple tubes in figured it might go on out but it just keeps mowing

A little STP and fill it up with grease worked for me years ago.

My shredder is leaking out of the gear box PTO shaft. It looks like an easy fix from the videos I've seen. I’ve also seen several videos that fix it by using the John Deere cornhead grease.

If the Kubota place gets my parts in today, I have a good excuse to go to Waco and also stop by the JD place for the corn head grease. In the meantime, I did put the gear oil on the gear box and shredded about 10 acres just now. Before I do any more shredding, I’ll put the corn head grease in the gear box. The next 10 acres up on the rotation are some very heavy grass and weeds.

Another question…do I totally fill the gearbox with the corn head grease, or just up to the weep hole?

agree, fill er up with grease and get back to work. My dad had an old 5' shredder that had been used on 4-5 different tractors over a 30 year span. He'd pull the plug at the beginning of shredding season, pump it full of grease, replace the plug and get busy. There is no telling how many thousands of acres that little shredder cut over it's life time.

That seal is pretty easy to replace. Its the one on the bottom that is a real pain.

Id try to get it about 3/4 full if it will take it. Not sure where your fill plug is located, most are around 1/2 way. but id try and get a little more.

X100 grease & done!

Got the grease. Tomorrow I’ll pump it in there and shred a bit.

The fill hole is on the top (kinda square housing). The weep hole is about half way down one side.

Open up the weep hole and dump it in until it pours out. Put the plug back in then put one more tube in it.

That’s about what I did. The gearbox is about 80% full. Once that was done, I went out to a rear field and put it to the test. Much quieter than it was when it had no gear oil. And before I put the grease in, I used a liquid extractor to remove the gear oil I had put in there recently. I was pleased to see that if I had lost gear oil, it wasn’t much. I tell myself that the leak/seepage must not be too bad, and the corn head grease should do the trick.

By the way, when you go to the John Deere parts department, it’s corn head grease and not corn hole grease.

And…thanks much for the grease suggestion, Big Country.

Yep the bottom one on a Bush Hog is a real pain, thankfully I have a good #6 Rosebud Tip for my cutting rig and a nice big set of gear pullers. Otherwise it would have been near impossible.
I will keep the corn head grease suggestion as a quick fix if I ever need to, great idea.

Checked the shredder gearbox to see if I’d lost any corn head grease. Yes, I had lost about half (one grease tube worth). When I unscrewed the vent cap to check the grease, there was a bit of air that blew out, so there was some air pressure in there. I wonder if the pressure is causing some of the grease loss. Tomorrow I’ll get a new vent cap and more corn head grease. If that doesn’t help, then I go to that Mystic red grease. If and when everything fails, I’ll get a new gearbox.

And my yard corn feeder motor died. Other than that, it’s a nice day.

You may have not lost any, it may have just settled. Add a little more and see what happens

I added a tube of the corn head grease. Hadn’t considered that it might have settled. I’ll mow some more in a few days and check the level again. I’ll also go by the JD place and get a couple more tubes. It’s pretty inexpensive, so that’s good. Not buying a new shredder. If the gearbox needs replacement, I’ll just get that done. The rest of the shredder is fine, though a bit roughed up looking. About 10 or 12 years old. For the record, it’s a 720 Squealer Bush Hog.

Update. The corn head grease seemed to be leaking out a bit, so I added some more and put some Mystic red grease in there too. That seems to be holding steady. I have myself a little dipstick for checking. If I can make it through the growing season, I’ll get a new gearbox put on it.

We've been running red grease in our gearboxes on the 6ft Howse and 14' woods for years, no issues. I just carry a few extra tubes with me, and a gun and stop every hour or so and check them.