My little brushhog on my little tractor is leaking oil from the base pretty badly to the point where I can't really use it now. Is there a seal there I can easily get? Could the housing be cracked? I've abused it a few times.

I forgot the brand, I'd look but its up at my land.

Its red and I think the brand is maybe just brushhog, think the sticker on the side has blue lettering on it with white background.... I think it's like 4 feet wide.



If it's just the seal could I take it apart, clean it up with a wire brush and RVT it?


Thanks, I really need to mow up there.


Also I've been using 80/90 gear oil in it. Is this ok?



Thanks in advance!

 

Gear oil is fine.

I can't see how RTV would help you, it is likely leaking around the shaft not around the housing (if in fact it's the seal leaking and it likely is).

You'll have to take off the spinner that has the two blades attached and pull the gearbox off, you might be able to clean the shaft up with emery cloth and pull the seal with a seal puller or similar tool and press a new one in. The gearbox is likely smaller than a football so you could take it to a parts store and they should be able to measure the shaft and the housing and get you a new seal.

Check for play in the shaft though, if I bearing went that shaft could be wobbling and destroy the seal quite quickly.

I'll bet a new seal and you are off to the races again, dirt will stick to it and wear the seal out over time and you loose your oil.

It's a very simple machine so should be pretty straightforward.

 

Thank you, I know of a little machine shop in the back of a parts store I can take it too.


Pretty easy to take apart? No springs are gonna shoot out and make me wonder "where the heck did that come from??"? Seems to happen to me a lot.

 

1. wash your brush hog so you can find the leak.
2. replace the offending seal.

 

A bush-hog's two biggest enemies are wire and "grass-string".


I will almost bet that one or the other has wound around the blade and worked its way up the shaft, until it got into the seal.

Either one will also groove the shaft, such that a new seal will slow down the leak, but not stop it.

The string will actually do more damage than the wire.


To get at the seal, remove the blade, then you can un-bolt the gear-box off the top of the platform and take it to the work-bench.


There should be a "shear"-pin that, upon removal, will let you slide off the PTO-shaft.



Do not attempt to fix it with the gear-box still on the platform; many are killed/maimed each year doing just that.

 

Yeah thanks much. I'll make sure the fuel is killed and the gear box is in N.

 

If you put the tractor in neutral, make sure that it's blocked well. Don't want it rolling over you or your truck. Just stating the obvious.

Most of those gearboxes are pretty simple; just gears and bearings. If you find that a new seal will only slow the leak down and not fix it, one of the tricks that we used to use was to push a full tube of gun grease into the gearbox and then top it off with 90W gear oil. Not good for close tolerance bearing like in the Getrag transmission but if the box it pretty worn anyway, it sure makes the leak slower.

Good luck with it.

 

Thanks again, I think it's past the point of grease working but after getting it back together and it still leaks some I'll do that.


Also how about some like 140 weight gear oil, would that hurt it?

 

I don't see any reason that 140W would hurt it. If it were brand new and had tight tolerances, it might not be recommended but for an older gearbox that has some wear on the bearings, I'd sure give it a try.

 

There won't be any springs or nonsense to jump out at you, it will be a very simple gearbox.

What Bear Killer said is true on lots of mowers, and other pieces of equipment for that matter and it could have picked up some wire or something. Around here I end up with plastic bale string wrapped around everything and it definitely will wipe out seals every quickly. I inspect every time I use a piece and usually end up cutting some off or unwinding it from the offending piece. On a bush hog type rotary mower though there is generally a "stump jumper" a large metal disk attached to the output shaft of the gear box. Two blades will be attached to the outer edges of the "stump jumper" on opposing sides and they are free to swing back and forth on those attachment points, they are flung outwards due to cytrifigal force of the stump jumper spinng but not being connected solidly prevents dammage to the gear box and driveline/tractor when you hit rocks or other obstructions that brush mowers are prone to hitting. (Generally they are attached with a bolt through a bushing) so washing and such you still will likely not be able to see the end of the gearbox where it is leaking.

You will probably also find the bolts that attach the stump jumber and or blades will be rusted and seized pretty tight because the grass really rusts stuff up. Try a good penetrating oil, shock them with a large hammer and a punch, I usually use an impact but I'd caution you with that one because you can snap those bolts quite easily, a little bit of heat helps too.

So that's what I'd suggest anyway. Take the stump jumper off, you can leave the blades attached, the PTO shaft is likely just attached with a 3/8" shear bolt on the input side of the gearbox, their will likely be 4 3/8" bolts that hold the gearbox to the mower deck. Take 'er off put it on the bench and you will probably see the dammaged seal on the output shaft.

If you have the gearbox on it's side or upside down, oil will likely run out the vent cap on top of the gearbox so maybe drain it first.

Replace the seal, fill it back up with your 80/90 ghear oil and put it back together.

Piece of cake.

 

Took the words right out of my mouth. If its a true bushhog brand mover or similar he basically stated verbatim what to do. Be sure to have a torch, you'll need it to heat things up with.

 

Thanks again guys.

 

Speaking of vents, check the vent on the top of the gearbox first. If it's smashed and not venting, that will cause high pressure in the gear box and you will just blow that bottom seal out again. Besides, the vent tube is alot easier to fix than a bottom seal. I speak from experience.

 

If the shaft is grooved I usually will measure the diameter and go to a good farm store and order a speed sleeve to repair it. If the grove is very big make sure you put some filler on it before you drive the speed sleeve on.

 

If you don't use the mower alot just mix gun grease with a can of STP and mow. Check it each time before you use it.