Home Forums Hunting & Shooting Hunter's Campfire Any farm mechanics on here? I need some help

I have a John Deere brush hog, fourteen foot, solid deck. Old one probably late 60's early 70's that I am trying to repair. It has two blade assembly's seven feet each. I initially thought that the key on one side of the assembly had sheared. Does not seem the be the problem, but I still have to remove the blade. I can't seem to get it off. Should be a tapered shaft with a key slot, with a bolt in the end of the shaft. This is how the other side is, that I fixed a few years ago. Anyway, I have the bolt removed, and have been using penetrating oil (PB Blaster) and hitting it with a hammer to vibrate and help it penetrate. No luck, so I have hydraulic jacks on each side of the shaft, putting pressure on the blade assembly, while vibrating with oil. No luck. This morning while pressure is applied, I tried heating up the blade part to a light red. No luck. I am thinking may next is cherry red, with pressure. All ideas appreciated. miles

Enough room to put a 2 or 3 jaw puller on it?

Heavy duty one that you can hammer on with an impact.

Did you get pin “key” out? If not it ain’t coming off until you do.

Good luck

Send me a PM, and I'll respond with an email and/or a phone number. I can offer a good way to get the assembly off that has worked for me many times, but I'm not about to engage in a pizzing contest with the troll patrol that hangs out here.

What kind of key?

Keyed, tapered spindle in a tapered hole…worst case scenario: key sheared and it was run long enough to friction weld together. (It can happen in seconds) If this is what happened, it would be why you couldn’t get it off and why you think the key didn’t shear. Fixing it would probably mean tearing the whole thing down to get the spindle out and replacing both components. Hypothetically, the blade could be saved, but you might find it difficult to find a machine shop where anyone knows how to do that these days and by the time the dust settled, you’d probably have the cost of a new blade invested in saving the old one. Hopefully that’s not what’s going on here.

Best I recall it is 3/8 square x 3 1/2 to 4 inches long. End of the shaft is hidden up above the blade with a cup above and a small hole through the blade with a bolt into the end of the shaft. Seems like the shaft is broken up in there somewhere. Blade has to come off to remove from the top. Blocking the input shaft above, gears do not turn in gear box, but blade a lower end of shaft does. I repeat, blade has to come off to remove the rest from the top. A couple of years ago, the key sheared on the other side, and the whole thing fell off in the field. Bolt came unscrewed when the key sheared, and bolt, washer and blade were laying in one spot. miles

I hope to hell youre ignoring the person(s) that have the answers to help you

Sometimes they could be different because they don't receive equal power.

I guess I would double check for a set screw and heat the hell out of it.


Your john deere man could probably print you out a parts diagram that could help.

Miles, there are a lot of knowledgeable and experienced guys over at My Tractor Forum. You might get some good help there, maybe from someone who's had the same problem.

I had a problem with a JD planter many years ago, and I went to the shop section of the local JD dealer, and asked around until I found someone that could address my problem. I know times were different then as opposed to now, but that might be an option.

Also, check to see if the side you're having trouble with matches the other side as far as the gearbox is concerned. It's possible that it's different, and the blades attached differently.

I dunno about that brush hog. But I do know you can blow up a couple pullers, before you find that secret snap ring that some azzhole engineer stuck in for no good reason.

After spending way to much time and some $$$ on belt driven bush hog, I gave mine to a young man and bought a new JD bush hog with only one gearbox and no belts.
JD even delivered the new bush hog to me. Best $600 I ever spent!

That may be real hard to impossible to remove, Miles.

By the very nature of a bush hog, the steel is exposed to the corrosive liquid from the plants then left out in the elements to compound that corrosion.

I had a batwing wheel assy that had to replace a couple years ago. I tried everything you mentioned, and after hours of heating with a torch, expanding the axle housing, and beating it with a 16lb sledge, I finally got it out.

Mentioned it to my service manager at the tractor/bushhog dealership, and he said they find those, and cut the axle housing, expand it with a cold chisel, remove the axle and then beat the housing back and weld it up...

Heaven forbid those manufacturers use some anti-seize.

Getting the drum and blades off a brush hog got into this one time with a smaller one a little 6 ft model. Took everything loose and it should be hammered cusp pulled nothing can get the drum off the shaft is kind of tapered. Finally put the nut back on loosely fired up the brush hog and lowered it down on a stump and let it bang around and sure enough it came right off the.
Now that was set up with shorter blades and a drum considered a stumpjumper. If yours doesn't have a stump jumper it might not be a good idea don't know that would be for you to size up and decide.
Jock it also try heating it up get it good and cherry red cool it up with a cold garden hose right quick and put the hammer to it kind of like popping a bearing off after you heat it.

Thinking that I need to get my Brother-in-law involved. He has a welding shop, and does work out on the farm for people. If it has to be cut off, He will be the one to weld it back. He might also have some tricks. My back is telling me to let somebody else work on it. Thanks all. miles

Please keep us posted, I have ideas but those bases seem to have been covered. Would like to know the solution.

I used to tackle any kind of a job repairing farm equipment, and have worked on a bunch of stuff over the years, but at my age I've gotten to the point where I usually take the hard jobs to the local Mennonite repair shops around here. They are extremely reasonable as far as price goes, as well as knowledgeable, do a good job, and I don't have to fool with it.

Try the simplest thing first.

Use a BFI.



(Big F'n Impact)

OK Gentlemen, some new stuff has come to light. I finally found an online diagram of the gearbox and shaft in question, and there is another key holding the top gear to the shaft. I should be able to take it apart from the top, and if that key is sheared, which seems probable, I will not have to take the blade off at this time. The equipment number has been gone ever since I owned it, and it took a lot of guessing and looking to come up with the diagram. By the way it is a John Deere 727, 14 foot rotary cutter. Have another project this morning, but will start trying to take it apart from the top this afternoon, or at least soon. miles