bush hog vibration

[anthonyk]

I've been using my Bush Hog SQ600 for basic light to medium work. Mostly small brush, weeds etc. Rarely anything bigger than 1 inch. I'm pulling it behind my new Century 3647, with the 47hp Cummins. Plenty of power, and I'm running it in the 540 mode at about 2600 on the tach, as specified.
Once in a while it just starts to shake the whole tractor as if the blades were unbalanced. Sometimes, it'll right itself and smooth out, other times I've got to stop the thing, let the blades stop and then re-engage the pto. I've checked the blades and they appear undamaged.
It's really annoying, and the extreme vibration can't be good for the tractor. Any ideas or suggestions as to what could be causing this, and what to do about it?

thanks, Anthony

 

[KiotiJohn]

When my brush cutter has done this, I have found that on some level it's not quite seated right between the lift arms and the tail wheel. Also, there can be times when something gets temporarily wrapped around on blade, making it out of balance. When it's severe, always lift the deck and look under to see if you have something wrapped around it.
Another cause can be a temporary sticking of one of the blades causing one to be in and the other out which would unbalance as well. I find it happens on mine most often right after I've gone through something pretty high and I've slightly lifted it up some, but goes away when I move off and lowever it back. I think in that case it may be that a lot of the cuttings have not cleared the stump jumper and blades qutie yet. I hope one of these helps some. John

 

[OkieG]

Sticking blade is what I've found when I check. A squirt of WD40 and you're back in business.

OkieG

 

[MicroPilot]

I've got nearly the same setup (slightly different tractor, same cutter) and have experienced this too. The first few times I would shut everything down and check under the deck only to not see anything out of place. Now I do as you said and disengage PTO, let cutter spin down and then re-engage. If it were to continue to vibrate then I would shut down and check the deck.

 

[Phred]

Well the other guys may be right ....
But my expereince is that its the blades.

I have a 286 which is about the same thing mybe a little bigger.
After a couple of years of use I had a tremedous amount of vibration.
New blades and new mounting bolts and it's like a new cutter.

When I looked at the blades they did not appear that beat up. Sure a little nicked up here and there but no radical visible difference. I could not tell that the old set was radically bent up.

Fred