Used brush mower - Maintenance issues.

[mainerr]

I bought a brush mower that was very lightly used, but had been stored outside.

After about 6 hours of use, two things have occurred:

1. The rubber safety flaps on the front and back have torn up / broken apart. I am assuming because of age... is this normal?
2. All of it's gear oil leaked out. It was 2" from the cap when I checked it while inspecting it for purchase.

Regarding the gear oil, I started taking it apart to inspect the gasket but it seems like quite a bit of effort to get to that point. I removed the cover, then it appeared as though I needed to remove the blades and pull the unit off the body to get to the underside of the transmission casing. I decided to pause last night and do some more research first, as well as put in some cheap gear oil and see if I can visually isolate the leak point first. Has anyone else here dealt with a gear oil leak in brush mower before?

Thanks in advance.

Here are some photos of the brush mower as a partial indication of condition upon purchase:

 

[LD1]

There are about 5 places a leak can occur in a typical gearbox.

1. PTO input seal.
2. Output shaft seal
3. Gasket for input shaft housing
4. Gasket for output shaft housing
5. Fill plug vent

Find out where the leak is coming from before you decide what to do next. IF an output shaft seal leak....alot of people just run a thin 0 or 00 grade grease.

Alot of old timers would drain the oil out of a brand new mower and fill with grease. Because you can wad up string, fence, or whatever and toast the output seal, then loose all of your oil, and fry the gearbox. Putting grease in prevents a costly repair because grease stays put.

 

[CodeMonkey]

This is typical of any mechanism that has rubber parts and has been stored. Those parts can fall apart, especially if it has been stored outside and especially if exposed to sun. Rubber can deteriorate and oxidize over time, especially when exposed to UV radiation from the sun. Seals/etc. can start leaking, maybe from exposure, but also from low use as shafts/etc. resting on the seal and cause it to be out of shape, then when used it leaks - also, some seals do better when exposed to lube to keep them elastic.

 

[Gary Fowler]

I would look for the leak first. If it is a bottom seal that requires a lot of disassembly to repair, I would try the corn head grease trick first to see if that doesn't stop the leak.

 

[ottawarob]

Have you contacted BCS America? I've found them to be pretty responsive.

 

[joecoin]

I've replaced the rubber flaps on my brush mower three times in two years, but I use it a lot in heavy brush.

I bought a rubber floor mat and I just cut strips out of it.

 

[mainerr]

I've replaced the rubber flaps on my brush mower three times in two years, but I use it a lot in heavy brush.

I bought a rubber floor mat and I just cut strips out of it.

I've been going through some heavy brush, figured that may have something to do with it as well. Was wondering about repurposing another product to replace with - thanks for the tip.

 

[mainerr]

I filled the gearbox up with cheap Walmart gear oil to see how long it would go before leaking out while in operation. Turns out it leaks fine just sitting - all of the oil leaked out overnight.

Attached are some photos of the results. I am not sure if you can infer based on them as to which seal bit the dust. I do know it looks like I'm taking this thing apart and at this point I'd be interested in proactively replacing other seals and gaskets.

 

[mainerr]

try the corn head grease trick first to see if that doesn't stop the leak.

Is that the same approach as what LD1 mentioned?

LD1 - the would fill with grease to the same level they would fill with gear oil?

 

[LD1]

Yes, same level. But it don't flow like oil. So run it a bit and refill

 

[mainerr]

Friend of mine who is a mechanic for the town replaced the seals with new ones from Earth Tools and filled it back up with gear oil. Ran fine for a few hours, then I smelled gear oil while operating - leaking out of the bottom seal.

Question 1:

One hypothesis is that there might be too much pressure building up. He mentioned the top plug / screw may want to be aspirated. Is that true?

Thanks!

 

[LD1]

Friend of mine who is a mechanic for the town replaced the seals with new ones from Earth Tools and filled it back up with gear oil. Ran fine for a few hours, then I smelled gear oil while operating - leaking out of the bottom seal.

Question 1:

One hypothesis is that there might be too much pressure building up. He mentioned the top plug / screw may want to be aspirated. Is that true?

Thanks!

Yes. Top plug is normally vented. Might just be plugged with gunk.

As the thing heats up, it builds pressure. Has to vent because seals arent designed to seal pressure.

 

[mainerr]

Yes. Top plug is normally vented. Might just be plugged with gunk.

As the thing heats up, it builds pressure. Has to vent because seals arent designed to seal pressure.

Thanks. Here are some photos of the top plug as it came to me. The top plug doesn't look so bad to me, but I'm not familiar with what to look for.

The bottom seal seems to be leaking pretty badly - I assume that if it was due to pressure build up, the seal has been compromised and I'll need to take it apart and reseat the seal / install a new one?

If it wasn't due to pressure build up, is there anything else? I think my friend ruled out a cracked gearbox...

 

[mainerr]

Here's a view of the leak / stream

 

[mark in portugal]

I seriously doubt the problem is due to pressure buildup; but there's a simple way to find out.
Loosen the top plug; still leaking out the bottom?
Now you know.

I suspect a problem with the seal installation; most likely the shaft that wears against the seal is rough / corroded, and spoiled the new seal. Other possibility is a loose / worn out bearing, but that would have been obvious.

 

[mainerr]

"Friend of mine who is a mechanic for the town replaced the seals with new ones from Earth Tools and filled it back up with gear oil."

I'm on the fence between taking it apart myself out of curiosity vs. just going ahead and filling it with grease and moving on with my life.

Will grease significantly lower the service life of the unit? Is it worth it for me to go through the paces myself in the case that it's something silly?

I know it's hard to quantify... but what would you do?

 

[Turbys_1700]

My dad used grease in his old bush hogs for years. It's what an old frugal farmer does. As long as the gear box is lubricated it will run. I would try it. If it works great. If not replace the seal.

 

[leonz]

That oil seal o-ring does not look good at all and is where you oil is going most likely. At this stage I would just invest in some corn picker grease to lube the gearbox and enjoy breaking new ground for a fall green manure crop.

 

[mainerr]

Thanks for the responses folks. I picked up another used brush mower to use in the meantime with the intention of taking this apart over the winter to get a better look at it for myself. If it comes to it, I'll throw grease in and use it for the rougher areas.