Is my bush hog dead?

peteinthehills · Feb 20, 2017

My bush hog was making some odd noises and so I investigated. It looks like it's never had any gear oil. OK, I know I should have checked once I got it home, but I didn't. I've attached some pictures. If I pick out the bits and fill it full of oil, will it be OK? It is just case of sticking it back in and tightening the bolts? I was going to use some gasket sealant to seal the connection.

Actually, how do I fill it full of oil? the hole at the top is quite small...is there a special oil filling device?

Any advice?

thanks

Pete

Stimw · Feb 20, 2017

They are not supposed to be full, there should be another plug on the side.
You remove both plugs and fill until fluid runs out the lower hole.
I would add about 25% STP or some other super lub to help it out.

KYErik · Feb 20, 2017

Yes- putting it back together is worth a try rather than just replacing parts. Do either of the shafts feel loose? Hopefully the lower oil seal is still intact.

In terms of filling it- you can buy a filler hose that threads onto a gallon or quart jug. Walmart probably sells them in the automotive department.

peteinthehills · Feb 20, 2017

thanks for the replies...neither shaft feels loose and it was quite a struggle to get it apart. I think the tricky part will be getting the bits out. It doesn't have to do a perfect job as long as it lasts another season. I might tip a bit of oil in there to see if it holds or if it leaks out. I guess it's better to try that while its apart rather than seal it up and then have to take it all apart again.

George2615 · Feb 20, 2017

You can buy gear lube in a squeeze bottle. Just cut the tip and it will fit in the hole to fill to the mark. Usually about half way. Most new equipment is shipped dry and the owners manual states how to add lube before using. Not sure how long you used it dry but you may have damaged the bearings running them dry. The gears don't look right to me either but try adding lube and see how bad the noise is.

DK35vince · Feb 20, 2017

Doesn't look good to me.
Looks like it was rubbing the case like the bearings are already toast.

flyerdan · Feb 20, 2017

There is a lot of wear on those gear teeth, it's gonna be noisy. Clean the metal dust and grit the best you can with solvent and compressed air, put it together with new seals if necessary and fill it with half whatever it calls for and about half moly gear additive. Moly really works; my dad bought a boat that had an old outboard with the gearcase in just as bad shape, you could barely turn the prop by hand. He cleaned up the rust and filled it with moly dosed lube and the longer he ran it the smoother it got.

peteinthehills · Feb 20, 2017

I bought the tractor and bush hog second hand...neither were well cared for which is why they were cheap (and why I could afford it). With help from a knowledgeable friend we fixed the tractor engine issues - bent piston rod. I've just tested for an oil leak in the gear box and of course there is a leak which is why its empty. I guess I can take the whole thing apart. At least it'll be a learning project if nothing else. Are there any good you-tube videos about taking bush hogs apart? The only one's I've seen use a large grinder and I don't see how they were going to put it back together. Should I try to take the housing off the top of the gear box? or do I need to attack it from underneath?

flyerdan · Feb 20, 2017

I've never worked on a bush hog, but they seem pretty simple in principle. With the blade and whatever it mounts to removed, the vertical shaft and gear (pic 1) should lift out and be removable as is. Then you can drive out the seal from the inside. Of course there should only be about 4 bolts holding the gearcase to the housing, and if you can take it off it will be easier to work on and it can be cleaned thoroughly in the parts washer and reassembled on a bench where it's easier to work. Be sure and check the shaft that the seal goes over carefully, don't want any burrs or excessive rust to tear the new seal from the get go. I clean them good on a wire wheel grinder and put a thin coating of white grease on the shaft to make it as painless for the new seal as possible. If there is a big groove scored into the shaft right where the seal runs (which is quite possible with the abrasive mix that was in there) you might still have a leak. won't be able to tell until the shaft is out for a look. If you know who made the hog, you can possibly find a manual with a parts breakdown on one of the free manual sites.

peteinthehills · Feb 20, 2017

ok, I'll give it a go. The housing is held down with 4 bolts, but the gear looks too big. I wonder if the housing will lift off? Still, that's tomorrow nights job. Ultimately I don't mind how it sounds as long as it does the job. The land I have is rough and it's mostly about keeping it straight until I'm more organised. I'm new to this and learning all the time.

gwstang · Feb 20, 2017

I would just get a new gear box and fill it and forget it. There is a reason there was no oil in it. Probably a bad seal and it leaked out over time. A way around that was to just use grease in the grease gun and it would last a long time. You didn't say what size yours is, this place has good prices on stuff like that.
4Hp Gear Box Splined

em14 · Feb 21, 2017

I would suggest use 0 or 00 Corn or Cotton head lub and just check the level every once in a blue moon! That is after you replace or rebuilt the gear box on the cutter!
Leo

Hiltz · Feb 21, 2017

Fill it up with grease and use it till it flies apart.

HarryVanderpool · Feb 21, 2017

Hiltz said:
Fill it up with grease and use it till it flies apart.

The problem with that idea is that when it "flies apart" your tractor PTO may be damaged.
Is there a slip clutch or shear pin?
If not and the unit were to seize, you could end up with much bigger problems.

NC419N · Feb 21, 2017

The main worry I would have now would be the bearings. They like grease/oil as well

bspeedy · Feb 21, 2017

Hiltz said:
Fill it up with grease and use it till it flies apart.

Don't start replacing parts in the gearbox. Put some corn head grease (00 grease) in and run it. If it doesn't work, replace the gearbox with a universal cheapie.

Soundguy · Feb 21, 2017

rinse it with mineral spirits.. that will be a quick seal check as well.

iF IT HAS RUN WITH NO OIL LONG TERM, i WOULD BET THE SEAL IS GONE.

iF SO.. AT THIS POINT, PACK IT WITH #2 GUN GREASE, ( caps.. ugh )..

then top it with a few ounces gear oil

peteinthehills · Feb 21, 2017

ok, I had a go at taking the rest of it apart and it's well and truly rusted solid. I'm going to try the grease option. Once I clean out the mess, get it lubricated and see what happens. Who knows I might get lucky.

It's just got to last long enough for me to save up and get a better second hand one.

thanks for all your help. I'll let you know what happens.

seaneastok · Feb 21, 2017

peteinthehills said:
ok, I had a go at taking the rest of it apart and it's well and truly rusted solid. I'm going to try the grease option. Once I clean out the mess, get it lubricated and see what happens. Who knows I might get lucky.

It's just got to last long enough for me to save up and get a better second hand one.

thanks for all your help. I'll let you know what happens.

Pete I said this same exact thing ...I got tired of replacing seal's etc...and the gear set looked about the same as your pic... I packed it with #2 grease and give it a yearly squirt of 90 wt gear oil to keep it flowing..That was 15 year's ago...granted I have different hog's that I use but the ol girl is still up and running..I basically sided with Hiltz...run it till it quit's then replace with an aftermarket box...