# Clutch & PTO Question



## Ubelongoutside (Sep 26, 2020)

Looking at some older tractors and have some questions about clutch and PTO terms. 

1st question: what does "over-running" mean in terms of a clutch and is it different than a 2 position clutch that will disengage the transmission for shifting, but not the PTO? Specifically for a JD 650. 

2nd question: what kind of pros and cons am. I looking at for an overrun coupler for a Ford x000. 

Thanks,

Don


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## Tx Jim (Jul 28, 2020)

Over-running clutch on a JD 650(keys 29 & 30) is a drive mechanism that transmit power in one direction & acts similar to a ratchet when power transfer is stopped. The spring(key 28) applies pressure to the components.

What pto does the Ford X000 possess? Only trans driven pto requires an over-running clutch. Dual stage clutch & IPTO have no need for ORC.


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## Ultradog (Feb 27, 2005)

Ubelongoutside said:


> Looking at some older tractors and have some questions about clutch and PTO terms.
> 
> 1st question: what does "over-running" mean in terms of a clutch and is it different than a 2 position clutch that will disengage the transmission for shifting, but not the PTO? Specifically for a JD 650.
> 
> ...











As TX Jim said, an ORC works like a ratchet and only transmits power one direction.
There are 3 different types of PTO on tractors:
Transmission, Live and Independent.
The Only time you need an ORC is when using a bush hog type rotary mower behind a tractor with transmission PTO. Rotary mowers develop a HUGE amount of inertia and on tractors with transmission (non live) pto that huge inertia 
can propel you forward - into the garage, tree, wife's car, ditch - even with the clutch pushed in and your feet hard on the brakes.
Other PTO implements like a sickle mower, finish mower, post hole digger, manure spreader, etc do not develop much inertia so an ORC is not needed on those.
There are a couple of types of ORCs. Both hook onto the PTO shaft in the back of your tractor.
First one is pinned on with a roll pin. The second and type I recommend costs more but are easily removed with the push of a button.
First photo shows the pin-on type. Second photo shows the push button type.


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## Ubelongoutside (Sep 26, 2020)

Ultradog said:


> View attachment 63533
> 
> As TX Jim said, an ORC works like a ratchet and only transmits power one direction.
> There are 3 different types of PTO on tractors:
> ...


Thanks for the detailed explanation. This helps me to understand.


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## Ed Williams (Jun 13, 2019)

My NAA would push me 60-70 feet with me standing on the clutch and brake pedals. Several scary rides before adding the ORC. Now everything is good. I bought the el cheapo from TC for less than $50 and it has performed well for the 7 years since install.


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