Bush Hog S072 shaking

[hslogger]

One other thought comes to mind for you and your vibrations. I rebuilt an old unit last year, and found that the four bolts that hold the gearbox to the deck had worked themselves loose enough that they needed to be tightened. Trouble was, the threads were pretty buggered up, so instead of running a bunch of washers to shim it,I cut he old bolts off or heated and removed them, replaced them with new bolts and lock washers. That fixed the problem.

Another aspect, like previous posters said, the arms are on bolts and if one gets stuck it won't swing out and that is a major contributor of this kind of problem. Now that I have my thirty year old unit sandblasted, primed and painted with epoxy underneath and above, with all new main bolts and swing bolts, I hose it down once in a while and figure with water and grease it will last another thirty years

 

[JRobyn]

There's not really a lot on a simple rotary cutter that will cause SEVERE vibration EXCEPT for something with the blades. Anything else (bent PTO shaft, loose gearbox, chunks missing out of the stump-jumper) would likely be very easily noticeable. As others have mentioned, anything to prevent the blades from swinging freely on their mounts is a common reason for vibration. Other than that, I'd remove the blades and weigh them or hang them on a teeter-totter balance to ensure that they are identical (or at least very close) to the same weight. It may be that a previous owner replaced ONE blade in the past and that the blades are now badly mis-matched in weight. Good luck fixing it!

- Jay

 

[dieselcrawler]

I have noticed that even a slight bend in one blade will make my brush hog vibrate. Bought new last summer, ran smooth as you please... hit a dirt crown, which sucked in the blade, bending it to where it hung about 3/4" lower than the other blade. I heated it at the bend, put it back to match the other blade, ran smooth again. Noticed yesterday that it's starting to vibrate again, I need to check the blades, as I have not done so this season.

If in doubt, replace both blades with a new matched set.

 

[marvinminor]

Thanks for all the help. I turned it over and the whole stump jumper and blades was wobbling up and down. I removed the nut with cotter pin and removed the stumpjumper. The inside teeth, where it attaches to the splined shaft from the gearbox, were worn and would not fit tightly. I ordered a blade weldment and new blades and put it back together and it now runs so smooth and quiet that I keep looking back to see if it is running.