8n makes horrible ratcheting noise when PTO overloaded

I was splitting some logs today using an old PTO powered Unicorn screw cone splitter on my 8n. I'd done about 1/2 a cord, mostly 14" to 20" round oak, without any trouble, when I put in a especially large and gnarly piece of oak. The 8n hunkered down almost to stalling but kept on going, but the tractor let out an "ik-ik-ik-ik" noise loud enough to make me jump, like some sort of ratchet safety device under extreme overload might make, or maybe stripped gears rubbing against each other.

It had a real bad sound to it, so I immediately killed the engine (though not before it finished splitting the log and stopped making the noise). The noise had sounded so bad that I was sure something big must be damaged inside so I wiggled the PTO shaft back and forth, drove the tractor around in each gear. engaged and disengaged the PTO, ran the lift up and down, and even split a few more logs. Everything seemed entirely normal.

So what could have been making that horrible noise? I know the splitter doesn't have any sort of overload protection, and I am pretty sure the 8n PTO doesn't.
 
8N PTO overload protection is the limited HP/torque of the engine. I have "killed" them from speed any number of times by whacking an obstacle with a rotary cutter and never tore up the PTO (yet) but it can be done!
 
(quoted from post at 17:25:34 04/25/15) 8N PTO overload protection is the limited HP/torque of the engine. I have "killed" them from speed any number of times by whacking an obstacle with a rotary cutter and never tore up the PTO (yet) but it can be done!

Possibly teeth on the PTO clutch skipping????

TOH
 
If it was the teeth on the PTO drive I would expect it to show up when I rotated the PTO shaft and engaged and disengaged it. And certainly when I split more logs.

Actually, it did sound a like an ORC, but much faster and noisier.And there is no ORC fitted.

I don't run the splitter very fast - fast idle, maybe 900 rpm.

There are some other more arcane possibilities. As the revs dropped the governor would have opened the throttle up all the way trying to maintain speed, This could cause
spark rattle or rod knock, or, some say, damage the liners.
 
i have 3 acres i cut wood on , i cut up the logs and bring them home and split them with an electric splitter .i had forgot all about those cone splitters until i read your post . how well does it work , is it worth owning one and do they still make them .that might make things a bit easier on my back (had back surgery a year ago )if you dont mind i'd really like to know about this splitter.
 
Here is one of my unicorn splitters. I still use them as backups to my hyd splitter or maybe when splitting way back in the woods. I think they were outlawed in this country years ago by the safety people in charge. They still made them overseas but instead of the pipe bar they use a table under it. I think there's some videos on youtube. Don't know if it easier on the back cause with either one my back is No good.

Kirk
100_3085_zps3ff41728.jpg
 
could also be internal at pto support. I've seen shafts twisted and bent so bad you couldn't get them out to drop the pump to replace, they had to be cut out on both end to remove. I hope this is not the case with yours.

Kirk
 
I just got mine running recently, and am amazed at how well it works. It's a Unicorn just like the one in Kirk's photo. Not nearly as scary as I had always assumed they would be. I have added a kill switch system triggered by a wire running across the splitter, so if one should trip and fall on it, flail about and hit it, or deliberately pull it, the motor will automatically stop. And I am thinking about adding a safety rail as used on most of the European versions, to keep me from falling onto the screw or PTO if I slip.

I really like the notion of a very portable 3 point hitch splitter which does not add another motor or hydraulic system to my flock. can be left outside, and mounted or removed in minutes without hurting my back. It is also, I was pleased to discover, much quieter than a small-engine powered splitter, since it runs at just above idle.

Most of the screw splitters were made to go on the rear axle of a car or truck in place of the wheel. I find these really scary. There were at least three companies making PTO versions, Barkbuster, Stickler and Thackery (who made the Unicorn and the B310 Kubota). Thackery also made several oddball versions including one that had a roller platform so you could just drive the truck onto it, another for the Gravely Tractor, and another powered by a Briggs and Stratton. A WTB ad on craiglist should find you your choice of models for $50-$150. Stickler still makes a rear axle version but not the PTO version. The main thing to look for in buying one is the condition of the point since even if is a replaceable one (they aren't, on some makes) they are no longer available.

I don't think anyone makes a PTO one in the US any more but they are very popular abroad. The Barkbuster was banned by the Feds after a fatality, mainly for the lack of a kill switch. But then it is absolutely nuts to run one of these without a (large, easy-to-reach) kill switch. It's hard to get a feel for how dangerous they really are. The thing looks incredibly dangerous, but once you use one for a while you start wondering what all the commotion is about, I figure it is probably about as safe as a chain saw and leave it at that. I also suspect that a modern redesign incorporating the safety measures used on the various Euro models would be very safe splitter indeed.

Oh, the manuals that came with the old screw splitters were sketchy and anyhow usually missing today. There are a few key concepts you must understand in order to use one safely - find someone who is experienced using them to help you get going!,
 
Kyle:

Is it possible that the cone splitter has an OVER-TORQUE Clutch built into it?

Just wondering . . . .


Doc
 

I have a conventional 5 HP Briggs and Stratton powered splitter. Sometimes with tough logs it can make various loud sharp noises as the log pops apart, then pops again as the wood splits. The splitter is bending slightly under the load and then snaps like a big spring as the load is released.

As time goes on and the old "N" just keeps on going with no apparent damage - perhaps what you heard was not the tractor. Good Luck.
 

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