PTO shaft or shredder out of balance???

[Zoombah]

My 5ft shredder acts like an out of balance washing machine on spin cycle. All the blades are present and accounted for. It's the only shredder I've ever had, and it was like this when it came with the tractor. Point is that I don't know what a smooth running shredder feels like.

How do I go about determining what's out balance? Could be the shaft or the mower itself.

Thanks

 

[RalphVa]

I'm assuming that you're talking about a chipper or chipper/shredder. My 2 MacKissic chipper/shredders were very smooth and well-balanced except for one time that I tried running the TPH-122 without its chipper blade. Then it ran roughly.

The TroyBilt Tomahawk chipper/shredder ran smoothly but was a noisey beast.

Ralph

 

[Hooked_on_HP]

Look at the ujoints on your PTO shaftand see if they are lined up. If the shaft was apart it may have gotten put back together wrong. Also check the length of your PTO shaft and make sure it's not to long and bottoming out.

 

[Inspector507]

I'm assuming that you're talking about a chipper or chipper/shredder. My 2 MacKissic chipper/shredders were very smooth and well-balanced except for one time that I tried running the TPH-122 without its chipper blade. Then it ran roughly.

The TroyBilt Tomahawk chipper/shredder ran smoothly but was a noisey beast.

Ralph

Ralph,
In Texas a shredder is a Rotary Cutter or brush hog.

 

[Brad_Blazer]

I think you are talking about a rough cut mower (RCM) ala Bush Hog? The most likely culprit is the blades. If you haven't actually mowed with it yet they might not be swinging freely. If they are swinging freely and there is no other obvious unbalancer like a rusted out stump jumper or piece of fence wire caught on the rotor it is probably a difference in blade weight. Hopefully you have an access hole in the top of the deck so you can remove the blades from above using a 3/4" drive socket set. The blade bolts are keyed to prevent them from rotating but if they are old and rusty you should use a pipe wrench on the bolt "head" to prevent the key from shearing when you remove the nut, especially after it gets somewhat loose. MAKE SURE you use jack stands when you are reaching under the mower. Another trick is to put a jack under the bolt to keep the key engaged after the nut starts to loosen. Once the blades are off you can compare them by weight and balance point. You can try to balance them as you sharpen them or if they are too far gone just replace them. New ones aren't terribly expensive.

My old beat RCM vibrates a little but not excessive unless something is caught on the blade. It runs quiet enough that the whistle of the spinning blades is very apparent at speed.

Brad

 

[Zoombah]

Yes....rotary cutter. I've mowed quite a bit with it. Vibrates so much it shakes the whole tractor...and me. Based on comments received so far I'll remove the blades and check for obvious things like wire or pieces broken off the spindle. With the blades off I'll slowly spin it up. If it runs smooth without the blades then we have the answer. If still out of balance then it has to be either the spindle or the PTO shaft. Am I missing anything?

 

[RalphVa]

In Oz, they call them "slashers".

I've had the blades cross or just plain not pop out on my brush hog. That really throws it out of balance at all speeds. First time it happened, I had to get under there with a crowbar to get the blades uncrossed. In subsequent times, I've been able to lower and raise the speed or maybe stop and start the PTO to get the blades to pop out.

Brush hogs, even with the blades out straight, aren't the smoothest piece of equipment out there. My neighbor's old JD with its 6' brush hog kind of oscillates like mine does.

Ralph

 

[Zoombah]

I do have a chipper but I would never refer to it as being a shredder. For literally decades before I actually had a rotary cutter I knew them only by the name shredder.

 

[N80]

I have a JD LX6 that will unbalance while mowing. I have no idea what causes it, and it isn't severe, just not as smooth as usuall. It will be running along normally and even though it doesn't seem like I've hit anything heavy or immovable (but i may be scalping or hitting larger clumps of grass I guess), it will suddenly start to vibrate. If I disengage the PTO, let it spin down and then engage the pto again, it levels out nicely and might not do it again for a long period of time. I'm assuming its a blade not straightening all the way out, but don't know for sure.

 

[hudr]

My 6ft does the same w/ new blades. Once the blades wear a little and loosen up it does fine. The vibration (in my case) was caused by a blade not slinging out straight after hitting heavy grass or a stump or something. You also need to check the stump-jumper (if equipped) and make sure it is not bent or missing big chunks.