Replacing seal in the bottom of a bushhog cutter

[clemsonfor]

I have a 4 ft Jbar bushhog. The lower seal under the mower is bad and i finally am going to replace it. Took the blades off and the power bar castle nut but cant seem to figure out how to get it off? There is a round plate that bolts to the bottom of the gearcase that the shaft then exits through, i figured if i pull that plate the whole shaft and everything would come out. Nope, all bolts out and a few taps of the 2lb sledge and no go. Now i m guessing that i need to flip it over and go up top and pull the side/top cover and look for a C-clip like on a truck axle, to remove before i can pull the assembly.

Any thoughts? I will try and get some pics posted today, but im sure this is a chineese gearbox that can be found on a range of light duty cutter from house to all the other light duty ones.

 

[SPYDERLK]

I have a 4 ft Jbar bushhog. The lower seal under the mower is bad and i finally am going to replace it. Took the blades off and the power bar castle nut but cant seem to figure out how to get it off? There is a round plate that bolts to the bottom of the gearcase that the shaft then exits through, i figured if i pull that plate the whole shaft and everything would come out. Nope, all bolts out and a few taps of the 2lb sledge and no go. Now i m guessing that i need to flip it over and go up top and pull the side/top cover and look for a C-clip like on a truck axle, to remove before i can pull the assembly.

Any thoughts? I will try and get some pics posted today, but im sure this is a chineese gearbox that can be found on a range of light duty cutter from house to all the other light duty ones.

No clip. That blade yoke and stumpjumper assembly was driven onto the shaft of the gearbox by that nut you removed. Most shafts are a splined taper. It will probably be extremely difficult to get it off. You will need to pull hard on the yoke/ power bar. Several tons probably. In a similar case I used a chain and portapower pushing from the shaft against the chain loop. 2tons, penetrating oil, tapping, and some heat were fruitless, but the 4T ram WAOTA got it off. A bit dangerous since the longer 4T ram could tip and fly if not well centered. A good 2 lock jaw puller would be the tool of choice. Just using grease in the gearbox is a trouble free option.
larry

 

[franklinute]

He's right the shaft out of the gearbox does have a taper for the stumpjumper to slide upon and tighten to. Sometimes splined others have a keyway. If you can get a large prybar close to the center of the stumpjumper you should be able to break it loose.

 

[clemsonfor]

Thanks, if its gonna take 2 tons of force thats about a no go. I thought about the pry bar thing, maybe that and a 3 jaw puller putting some tention on it. A 2x4 was no hope, tried that at first and the board was just about to break. I also have no stump jumper, just the powerbar.

 

[SPYDERLK]

3 Jaw wouldnt hold on mine due incompatible symmetry. 2 jaw would.
larry

 

[sandman2234]

I had one a few years ago, and I built a puller to get around the stump jumper (which yours doesn't have) and it took a LOT of force, to a point of almost bending the stump jumper, and then a smart (several tries) rap to the end of the shaft (threads protected!!!) and it finally came loose. I would SERIOUSLY recommend doing any and all penetrating oils and wax, etc before attempting the removal, as anything that helps might be just enough to get it off.
Grease was suggested, as a viable option, and I don't know of any drawbacks provided you can get enough grease through that little hole.
David from jax

 

[clemsonfor]

The 3 jaw that i borrowed from a buddy can have the jaws moved to be a 2 jaw, where the jaws oppose each other 180 degrees.

The bar ought to be lubed up good as it leaks a whole box full out in a couple days or so and its been like that for a year or so! I just fill it up everytime i use it afer a few weeks in the summer and just top it off each day i use it in a row.

I thought about the grease, i guess i was just wanting to do it right, but if im unsuccessfull i may do it. But if the box burns up i have to get the bar off anyway to put a new gear box on anyhow. I have read that guys use something like JD cordhead grease or something or a combo of that and straight grease.

 

[clemsonfor]

Success, partly. I took the plate loose to early and some random prying with a 3.5ft bar and some tapping the shaft i successfully pulled the shaft with the bearing and collar out of the box. I should not have taken the bolts out of the seal cover plate. Now i just tried to pull the power bar and shaft out, it would not come no matter how i pulled it so i just pulled and puled it while standing on the upside down deck, then i tried to push the shaft back in and was just thinking about grease as i could not get the parts apart. One more just pull and tap out of desparation and it just pulled off? So now i pulled the plate with the seal in it out and there was a wad of grass junk there which tore up the seal. Then i tapped the shaft back in mesh with the other gear and the plate once the seal is replaced willpull it all back to geather, hopefully. Thanks for the help.

The weird thing is that the seal/gasket in there was pieces of thin plastic?

 

[Ginormous]

Unfortunately, my "new" Woods 4' bush hog has a similar leak in the lower seal. After reading the discussion on doing the repair, I don't feel very optimistic about being successful trying to replace the seal -- as Dirty Harry famously said, "a man's gotta know his limitations." If I go the grease-in-the-gearbox route, can I use the same moly grease I use for all of my tractor grease fittings?

I see that John Deere Corn Head grease was mentioned above... Sounds like it's softer than normal lube grease?

 

[clemsonfor]

Unfortunately, my "new" Woods 4' bush hog has a similar leak in the lower seal. After reading the discussion on doing the repair, I don't feel very optimistic about being successful trying to replace the seal -- as Dirty Harry famously said, "a man's gotta know his limitations." If I go the grease-in-the-gearbox route, can I use the same moly grease I use for all of my tractor grease fittings?

I see that John Deere Corn Head grease was mentioned above... Sounds like it's softer than normal lube grease?

Its thiner than lube grease but still flows, which is why i think its better for a gearbox that may have the potential to be slung away from the gears and create a void where the gears are, esp in the cold.