# Liberty wood chipper wc-8 slip clutch



## JGPenfield (Mar 10, 2016)

I have the above wood chipper. On the implement end the shaft is splined and attaches to a splined end on the gear box. Therefore there is no shear bolt. But there is no slip clutch. I tried to attach a splined ended slip clutch but there is no way to attach it and even if I did it would hit the metal shield when it was spinning. Should this thing have a slip clutch. I have the manual and it does not mention a slip clutch. 


Sent from my iPhone using Tractor Forum


----------



## Hoodoo Valley (Nov 14, 2006)

I'd be of the school of thought that if it DID need one, that it would be mentioned, or there would be stickers highlighting that fact. However, you should call the manufacturer if in doubt.


----------



## RC Wells (Dec 26, 2008)

The model you list is also sold as a WoodMax chipper. I would go to their website and obtain the most current manual: http://www.woodmaxx.com/category_s/78.htm 

Compare this manual to yours to see if this is the same model as yours.

The advertisement states the chipper is equipped with a shear bolt. I read through the manual and did not find reference to the bolt, so assume it is on one of the drive yoke to shaft coupler ends on the driveshaft itself.

I would call the company at 1-855-966-3629 and verify the location of the shear bolt.


----------



## pogobill (Jan 31, 2012)

I have a shear bolt on my PTO shaft at the U joint end that connects to the implement. Could be hard to spot if you don't know it's there. I believe the chipper blade is powered by a belt, so the may be no need for a slip clutch, and if you keep your blades sharp you should have no problems.


----------



## JGPenfield (Mar 10, 2016)

I called Woodmax and asked if they bought Liberty and the rep said no and he gets a lot of calls asking about parts but can’t help them. I ran the chipper and it bogged down enough to stop my tractor and nothing slipped and no bolt sheared. This is not a tiny tractor. It is a Ford 3000 diesel with 47 horsepower and it takes a lot to stall it out. But it was a slow stall out and not like hitting a stump so fortunately nothing broke in my tractor. I will take pics of what I have and post them by tomorrow. I was hoping somebody with a Liberty chipper could respond, but where does one find a person like that? Liberty has gone out of business. I hate to run this thing without tractor protection. One option is to put the slip clutch on the tractor side. I do have a guard on the tractor side and would be behind the implement and not riding on the tractor while using it. 


Sent from my iPhone using Tractor Forum


----------



## RC Wells (Dec 26, 2008)

Compare the manual for the Woodmax to yours. I wonder if they are the same or similar.

Liberty went out of business about the time Woodmax come on the scene with their Chinese line of chippers. The only relatively current reference to Liberty Chippers I could find is a BBB rating of F, and a host of alternative and other Internet related sales business names in Arizona: 

Envy Liberty Holdings, LLC
Trump Ventures, LLC
and,
Home Furniture Direct, LLC

I looked at a friends WoodMaxx and the shear pin is a bolt in a tab that sets to one side of the PTO coupler. Here is what the end with a shear pin looks like:









It is possible your PTO drive shaft was replaced with a generic unit with no shear pin, which would be dangerous.


----------



## pogobill (Jan 31, 2012)

RC Wells said:


> I looked at a friends WoodMaxx and the shear pin is a bolt in a tab that sets to one side of the PTO coupler. Here is what the end with a shear pin looks like:
> 
> 
> 
> ...


This is the same as my drive shaft, I thought it was pretty standard. 

Do you have this set up. This manual shows a clutch assembly on page 20, first few parts listed. I think this unit may have also been sold as a Jinma Wood Chipper.


----------



## PJ161 (Sep 12, 2016)

If you can only fit a slip clutch or shear pin to the drive end of the PTO shaft, kinda unusual, then I would do it, to me, protecting the tractor is much more important than the implement in question! PJ


----------



## JGPenfield (Mar 10, 2016)

I don’t have that on my shaft. The implement side of the shaft is a simple splined end. Identical to the tractor end of the shaft. I have the manual and it mentions nothing about a slip clutch or shear pin though it does talk about adjusting the shaft length if needed. 


Sent from my iPhone using Tractor Forum


----------



## JGPenfield (Mar 10, 2016)

The slip clutch I have that will fit on the tractor side has a torque slip rating of 9000 inch pounds. My tractor engine is 47 horsepower and the PTO power is 38 horsepower. Will this slip clutch protect my tractor?


Sent from my iPhone using Tractor Forum


----------



## RC Wells (Dec 26, 2008)

Not even close. There are inch pound to horsepower moment conversion tables free on the net, and tons of engineering texts with the same information. All of the Western World uses Imperial Mechanical Horsepower to derive torque calculations.

One horsepower is 550 foot pounds, or 6,600 inch pounds.

You would need 250,800 inch pounds to equal your PTO horsepower. 

Slip clutches are never mounted directly to the PTO drive, but on the implement end because of dynamic balance requirements. They need to be supported by heavier lateral load capacity bearings than found on tractor PTO's. Implements that use slip clutches have large bearings capable of handling the lateral stress. 

Stop in at just about any farm equipment dealer and obtain the appropriate PTO driveline with a shear bolt. They are inexpensive and relatively safe. For shear protected PTO drivelines the shear bolt end mounts to the tractor PTO, no massive lateral stress is present and prevents the shaft from becoming a missle if a yoke breaks.


----------



## bandana (Sep 26, 2018)

Curious what route you went with this issue? Did you get a new PTO with the shear pin? If so what brand? I bought a used 2014 WoodMax a few months back and the PTO It came with does not have the shear pin either. I think its the difference between the standard - as supplied, PTO VS the made in America PTO you can special order for more money. I've been thinking of buying a new shaft for mine too - with the shear pin.


----------



## JGPenfield (Mar 10, 2016)

Thanks for the reply. I have not fixed my problem yet. I was confused about your rec. Should I get a PTO shaft that has a shear bolt on the tractor side instead of the implement side? If so, that would require an adapter to convert the splined end to a smooth end that would take a shear bolt. 



Sent from my iPhone using Tractor Forum


----------



## pogobill (Jan 31, 2012)

The shear pin should be in the universal joint arrangement and not on the splined PTO shaft. No need to change you splined shaft for a smooth one.
See item "M" on the drawing. It holds the two pieces of one side of the yoke together, and does not have any contact with the PTO shaft on the back of the tractor.


----------

