Brush Hog Stopped Mowing Suddenly

[djradz]

Andy, assuming you get the blade bolts off, I think I'd try mowing at a little higher setting and also adding chains to the front so you don't inadvertantly set the three point too low, even with the rear held higher with the wheel. I'm surprised that even with a cab, you don't hear, and FEEL, a rock large enough to break the blades. We hit plenty of rocks here in southern michigan, even in the overgrown farm fields that have had rocks picked for over 100years, but I've never seen a blade break at the bolts. Usually if breaks half way or as some point much farther out, if the blade has been worn or sharpened much and made thinner. Maybe Bush Hog has got a manufacturing defect and the blades are too weak or brittle? Maybe try a different brand of blade? Good luck.

... /forums/images/graemlins/mad.gif don't you hate those rose bushes???

 

[Steve_Miller]

I don't own a mower but aren't they the same as a rototiller or snowblower and have the proper shear bolt to protect them no matter what HP is driving them? I'm not being critical, just like you , I don't understand why they all broke off before the shear pin/bolt should have let go.

Steve

 

[DrRod]

Andy -- if its chains you're looking for consider a flail mower. They use chains (with T shaped knife blades at the end) to cut the grass. Not so good on brush but much more forgiving or rocks. They take more power but that doesn't seem to be an issue here. /forums/images/graemlins/wink.gif

 

[AndyMA]

Actually I heard plenty of rocks, but that is normal. This is a "new" mower and I used to run the same model on the 43 hp 2120. I always hit enough rocks, but usually you just dent the housing and beat the **** out of the blade. I've broken a few before but not like this. I was pushing it trying to get a lot cut before dark (and after dark with all those TN lights) It had started to rain. There probably is a shear bolt somewhere, but it won't do as much good on a mower as on a tiller or snowblower, since neither of those have anywhere near the same rotational momentium as the mower does. I believe it picked up a decent bolder and got it caught between the blade and housing and sorta pried down on the blade. The blate probably bent back on itself and jammed the rock in somewhere. As far as flail mowers go, I'd live one, just like a heavier duty larger brush hog, however the finances don't allow that right now. I used a Mott "Hammer Knife" walk behind flail mower back in the early sixties on my family nursery.

I am seriously looking into trying an actual chain to see what happens.. Stay tuned

Thanks for all your input. BTW, I probably have several thousand hours on Brush Hog experience and this is the first time I've dont this much damage to a mower. Too much tractor, to little mower and operator not really paying attention to what he was running over.. Of course they are touch to see when hidden inside a 12' high rose bush...

Andy

 

[Jagmandave]

I had trouble getting the blades off my ZTR yesterday, had a 5 ft pipe on a 1/2 drive breakover bar and broke the side right out of the socket! This mower is only 2 seasons old, and I've had the blades off before to sharpen them, so either I overtightened them last time or they self tighten due to the rotation. After I got the bldes off I noticed 2 off them were bent down towards one end, and I guessed that the block of wood I was using to block the blade caused it to bend down when I tried to loosen the nut with the cheater bar. Gotta watch that! Anyway, I went to Sears for a new socket, and while I was there bought a 3/4" drive bar and socket too. Even with the 5' pipe it took eveything I had to get them broke loose. When I reinstalled them, I put some lube on the threads and did not pull them so tight, hope I can get em off a little easier next time!
I had to take an impact wrtench to the bolts on my brush hog blade bolts to get them broke loose, and had to take the stump jumper off the spindle and put it on the floor to get to the nuts on top. It was just as well, the jumper was loose on the spindle, last guy hadn't tightened it up properly.......

You sure your gearbox is still OK?

 

[Tim_in_IA]

AndyMA,

Maybe with that much HP you could rent a crusher attachment and pulvarize those nasty rocks first. /forums/images/graemlins/smile.gif

I'd start mowing with the windows open and the earplugs out /forums/images/graemlins/smile.gif.

 

[normde2001]

I suspect those blades are frozen to the bolts and/or stump jumper so that they can't flex, which might explain why they broke. I lube and make sure mine are free before each use.