Rotary Cutter Bush hog rattling

[485didriver]

I use a 6' bush hog behind a Mahindra 485 DI tractor, and have some questions. My low range is out-completely (see my thread under Mahindra if you can offer suggestions on THAT one!), so I do all my bush hogging in H1. When I engage the PTO, the implement rattles like crazy, and seems exceedingly loud. Is the reason for If not, any other thoughts? Thanks!

 

[Mikeeemo]

Well we are wide open on this one... Lets start eliminating stuff.

Disconnect the PTO shaft from the tractor, engage the PTO and see if the noise stops.

With low range out, you may have parts floating around inside making noise in the transmission.

If the noise stops, I would inspect the brush cutter (is it a Bush Hog brand?) for loose parts, loose or sloppy joints in the PTO shaft, loose blade bolts, and tighten it all up.

Is the deck bent? Could the blades be banging on the sides or top?

Block the mower up with jackstands or timbers (engine off) before you inspect the underside.

Make sure the gear box has enough lube in it.

Good luck.

 

[have_blue]

I use a 6' bush hog behind a Mahindra 485 DI tractor, and have some questions. My low range is out-completely (see my thread under Mahindra if you can offer suggestions on THAT one!), so I do all my bush hogging in H1. When I engage the PTO, the implement rattles like crazy, and seems exceedingly loud. Is the reason for If not, any other thoughts? Thanks!

485,

Have you checked the drive shaft to see if it's bent?

Could the blades be touching the skirt?

Did it start vibrating suddenly, or creep up on you?

Have you mowed with it? (Could be a dirt dobber nest on the blade or a blade stuck partially folded).

 

[deere5105]

Was mowing beside an old fence and got a piece of barb wire hung in a 6' Howse mower. Got in between the blade and the stump jumper and binded so the blade couldn't swing freely. Mower shook severely. Had to turn it up on it's side and pull wire out with pliers. Thought I was going to have to remove the blades to get it out because the old wire kept breaking. After getting it hung I figured I could just reengage the PTO and break the wire and keep mowing and get it out when I got through. I figured worse case scenario it sheared the shear pin...wrong. I noticed it wasnt turning the mower and got to looking and the PTO shaft pulled out of the rear of the tractor!!

 

[485didriver]

Thanks for the replies!

It's not the tractor or the PTO making the noise. I just finished repairing the PTO (which HAD actually been pulled outta the back of the tractor!!), so I'm confident that's not the issue.

When I start the cutter, it will start up for the first 10 seconds or so, but as soon as it hits higher rpms, it rattles like mad. I must be honest, I dunno exactly how the drive shaft should look. I don't see any area that's obviously bent, but the plastic shell on it is pretty worn out. The bolts that hold the gear box down are fairly tight, though I note that when I turn them, they move a little bit. Haven't gotten up under it yet, mainly b/c I've been short on time and long on work, and b/c I don't really have a good way to block it up safely. Will work on that and get back with you!!

 

[kebo]

Do you have another PTO shaft on another attachment you could "borrow" and hook it up to the bush hog?? Or maybe you have a friend or neighbor with a similar PTO shaft that would let you borrow it just to see if the vibration goes away? By using another PTO shaft, you can see if it eliminates the vibration and go from there.

 

[485didriver]

Do you have another PTO shaft on another attachment you could "borrow" and hook it up to the bush hog?? Or maybe you have a friend or neighbor with a similar PTO shaft that would let you borrow it just to see if the vibration goes away? By using another PTO shaft, you can see if it eliminates the vibration and go from there.

Now that's an idea that I hadn't come up with! Matter of fact, I have a finishing mower that hasn't been used since I bought it (used), so I might look at it tonight and see if they'd be interchangeable. Will let you know!

 

[jenkinsph]

Have you balanced the blades weight recently?



Steve

 

[ohiokubota]

have you hit anything with it

i would make sure your blades are extending all the way

make sure everything is greased and moving freely

check your gear box oil also and bearing play

 

[ACWD45]

Thanks for the replies!

It's not the tractor or the PTO making the noise. I just finished repairing the PTO (which HAD actually been pulled outta the back of the tractor!!), so I'm confident that's not the issue.

When I start the cutter, it will start up for the first 10 seconds or so, but as soon as it hits higher rpms, it rattles like mad. I must be honest, I dunno exactly how the drive shaft should look. I don't see any area that's obviously bent, but the plastic shell on it is pretty worn out. The bolts that hold the gear box down are fairly tight, though I note that when I turn them, they move a little bit. Haven't gotten up under it yet, mainly b/c I've been short on time and long on work, and b/c I don't really have a good way to block it up safely. Will work on that and get back with you!!

towards the end of this vid:
is this what you are talking about?
YouTube - 1970 John Deere 4020 Turbo


If it is the shaking when he starts it, the swinging blades are just evening out (this is normal on most old bush hogs), if it is the ratteling when he revs it up, your oil reserves are dry, or its just getting worn out. A lot of old oned do this as well. It should be fine.