follow-up: new operator/old mower questions

I appreciate those who responded to my last thread.
I take seriously the safety aspect. Yet I bear risk in every task accomplished. I approached this unit with a wary eye and zero trust. I've many updates pending but for the price ($150) I took a shot. I realize this unit is old, tired, and worn. But the past weekend surprised me. Here's the story:
I started by opening the access bolt on the top rear of the gearbox. It was sludge! grey/beige goop. I dipped out as much as I could with a stick:


So, I filled it with "gear oil" leftover from some bottles I got at a rummage sale. Probably a quart's worth. mostly 90w and some 75w. It may not be the right stuff, but better than running without any oil, right?

Then I greased everything. To my surprise, ALL three grease zerks took grease! I filled the PTO shaft U-joints and the trailing wheel sleeve as best I could. They seemed loose, so probably need to do this regularly to keep the cavity full of grease.
I fit in a 1/2" bolt for shear pin. fully threaded, not the right thing, but it held for 2hrs of mowing.
I looked underneath: it's got holes but I don't see anything alarming. Maybe you do?


The moment of truth: power up. There were three nasty clunks! then, just a whirring hum. It works!
I drove around the field, it doesn't seem to cut, but more like break and fold the grass over. My tires were pounding the grass down more than the mower. IT was 'cutting' very tall, like 8" or so. Is that normal?
The front of the mower, I did my best to adjust the 3pt and keep them on the ground. It was uneven, so regularly dug trenches with the side rails.

Appears to me you are being prudent. Run It and see what happens. It probably has had tube grease added to make it thick enough to stay in.

So, I'm thinking this old thing is worth a bit more energy.
Reading your other posts, I plan to seek welding help to reinforce the front area and fill in the cracks.
Also will build some chain for the leading edge. I have access to a rusty old piece of junk chain that will be great to cut into pieces for a front hairline.
should I bolt on the chains? or weld them on?

I also planning to find an expanded metal gaurd for the back of the tractor. I felt very exposed on the open station with those blades whistling behind me!

Please share ideas or suggestions. and if you have pictures of your unit, I'd like to see them for ideas.

A lot of these older bush hogs have seals that leak under the mower, your's looks pretty dry. Corn head grease is your friend if you have a leaky seal, Go at it the way you are doing and you should be fine,
you probably need to sharpen the blades.

You want to set the front about 1/2 to an inch lower in the front than the back when cutting. Saves cutting twice. Guessing there is a full level plug in the back of that gearbox.
Not sure what cornhead grease looks like but they may have added it. Thicker to help keep from leaking.
I circled the plug in blue. Don't look like it would come out easily though and only matters if you change the oil anyways. You may want to check the play in the blade holders, the blades seem saggy, but could just be the angle of the picture. Have fun with your new cutter!

I would keep watch on the oil you put in, it may leak out. That's probably why it has grease in it.

If the small plug will come out, you can replace it with a grease zerk. Then get a couple tubes of corn head
grease. That's the slang name for grade 0 or 00 grease. It is thicker than oil so it stays in less than
perfect seals, but thinner than chassis grease so it doesn't channel away from gears.

If you can get a grease zerk in the fill level hole, then before each use, remove the upper plug and pump it
until grease comes out the top. That way you don't pressurize the gear box and blow the seals.

The holes and cracks can be plated and welded. Plating is much stronger than just trying to weld cracks,
that rarely works.

Really don't want a guard in front, that will fold the grass over and eventually get bent back and into the
blades. Maybe a horizontal hood to deflect anything down.

The chain guards on back can be welded, faster and easier than bolting. Bolt holes may start cracking.

use a chain for the top link other wise if you go through a ditch it will bind

The circled plug may be a level plug. Gear boxes are usually filled about 1/3 full, maybe slightly more. Have one without an obvious drain plug. I lifted it up with a loader and drained it through the fill plug. Also there should be some kind of vent in all gearboxes so when the heat up with use air can escape and not build up pressure. I have put street elbows in with a nipple pointing up, a cap on that with a notch or groove filed in the threads so they can vent but not let water in.

Good on you Dan! I was the odd man out when everyone was condemning your unit. It is just the nature of the beast that they take a beating in normal use. There are no doubt many that get used only for light hobby use and are no doubt washed after every use and every scratched painted with touch-up paint.

So nothing broke and nobody got hurt the first time out. That doesn't necessarily you have a good safe machine. Just be CAREFUL. The shroud isn't going to protect you from much being worn paper thin and having holes torn in it as I recall. That's what it's there for.

So when you start up a rotary mower with swinging blades like this, the blades are going to swing until "centrifugal force" straightens them out. They're going to come in contact with each other. That is going to make a clunk noise or two or ten.

The goop in the gearbox is grease because the bottom seal leaks. It is most likely too worn to hold a seal for long so changing it is a waste of time. Keep an eye on the underside of the mower. Likely the stump jumper will fill with gear oil and coat the bottom next time you spin it up. Gun grease is fine because even though the gearbox isn't "properly" lubricated it will heat up, melt the grease, the grease will flow over the gears and bearings, and lubricate the gearbox.

Your blades are DULL. They must be blunt as baseball bats. Sharpen them. They don't have to be razor sharp, but at least have a consistent wedge shape along the cutting tip.

Height is adjustable.

I'm looking at the pic showing the blades. That round disc they bolt to is called a stump jumper. This is not a rotary mower, but a light duty brush cutter. Do not expect to see results like a finish mower.

In that pic, I cannot tell if the stump jumper is bent or not. If not straight it can send the unit whirring out of control due to being out of balance. The blades also appear to be hanging quite low. Cannot tell why from the pic. But if that disc is damaged, it needs to be replaced.

As for how it cuts, I do not remember exactly what you plan to cut with it. If saplings/young trees, then that is correct for your needs. If you will cut primarily grasses (especially thinner or really tough grasses), then you will want thinner blades that cut rather than thick that chop/pound. I chose to do an alternative on my deck. I spend MANY hours grinding a nice, long sharp edge on my blades. I kept the weight for getting through brush, but had an edge for all the grasses. It worked great for my needs, but I'll never grind that much again!

Hope to hear one more update from you once you're all done with it.