641 PTO / 3 Point ?

[atgmz]

I have a Ford 641 tractor that I got as a project tractor. I want to restore it as much as possible but it also has to earn it's keep around the place, i.e. bush hogging, tilling, grading, etc. By reading this forum I got it running and have figured what everything does and why it does or doesn't do it. The parts that I have purchased were from here also, anyway. The tractor came with implements so I didn't have to buy any at this point. When I do discuss the tractor I am asked what type / category of PTO and 3 Point do I have..I don't know! I've used it but I don't know what type it is. It is obviously stock because it is exactly like in the manual... Can anybody help a city slicker who retired to the country?

 

[cb in wisc]

I have a 641 too, and they are catagory 1.

 

[old]

641 says it has a 134 engine, 4 speed tranny, live hyds but no live PTO. If you don't have one you need to get and install an ORC or one of these days you might just run over something you don't want to when using your brush hog. 641 was made from 1958-1962 and has around 33HP
Hobby farm

 

[atgmz]

(quoted from post at 17:47:57 11/04/07) 641 says it has a 134 engine, 4 speed tranny, live hyds but no live PTO. If you don't have one you need to get and install an ORC or one of these days you might just run over something you don't want to when using your brush hog. 641 was made from 1958-1962 and has around 33HP
Hobby farm

What I am calling the PTO is the splined shaft at the back of the tractor. There is a two speed lever on the side that can only be engaged when the clutch is pressed down and does not operate until I release the clutch. If I push the clutch in, it stops turning. This rotates my bush hog. Is this not the PTO or is there a difference between a live PTO and a PTO? Please help!! Like I said , I'm new to this and got into it when I went to an antique tractor show. I can use all the help I can get. Thanx

 

[Anonymous-0]

atgmz; when they say you might run over something you
don't want to ! the centrefical force of the HOG will keep the tractor moving when you release the
clutch , thus running over something ... old,,am i right or wrong ?
sonny

 

[awhtx]

Your 3 Point Hitch is Category 1. Go to the links on the left side of this page and look for "Research & Info". Under R&I look for "3-Point Specs". Click on that and it will give the specs for all categories.
You PTO shaft may be either 1-1/8" or 1-3/8" in diameter although most 1'1/8" PTO shafts have now been switched over to 1-3/8". If you are trying to hook up an implement that is PTO driven you must know which size shaft you have in order to obtain the correct size coupling. As others have posted- if you are using a bush hog on this tractor you need to install an Overrunning Coupler onto the PTO shaft for safety. Since you do no have Live PTO the spinning bush hog will push your tractor forward even with the clutch pedal depressed unless you install a ORC.

 

[old]

Live PTO means when you push the clutch down half way the tractor stops moving but the PTO keeps spinning at least thats how it is on Fords. And if you do in fact have a 641 it doesn't have a live PTO because when you push the clutch down the PTO stops and so does the tractor. With that set up you NEED an ORC because the blades on the brush hog will tend to try to keep spinning when you push the clutch down and that will then push the tractor forward another 10-15 feet which can be bad news if your in the wrong place or it can also lead to being dead. Seen more then one tractor end up in a creek or into a fence because of no ORC on the PTO
Hobby farm

 

[Michaels Dad]

(quoted from post at 20:24:52 11/04/07) Live PTO means when you push the clutch down half way the tractor stops moving but the PTO keeps spinning at least thats how it is on Fords. And if you do in fact have a 641 it doesn't have a live PTO because when you push the clutch down the PTO stops and so does the tractor. With that set up you NEED an ORC because the blades on the brush hog will tend to try to keep spinning when you push the clutch down and that will then push the tractor forward another 10-15 feet which can be bad news if your in the wrong place or it can also lead to being dead. Seen more then one tractor end up in a creek or into a fence because of no ORC on the PTO
Hobby farm

Since I'm still on the learning curve am I to assume that if you have to hit the brakes suddenly the clutch would slip thus stopping the momentum. If this is the case I’ll be at TSC first thing in the am to pick one up. Since the tractor is 300 miles from me now, can anyone give me a part number to go with my 640.
It may be redundant because of a shear pin on my brush hog, but if it helps to kill forward motion, that is one great safety feature I can use on my hilly terrain.

 

[awhtx]

MD- your assumption is incorrect. On the 4 speed transmission (and the 5 speed with the non-live PTO) the PTO is driven by gears inside the transmission. When the clutch is engaged the engine turns the transmission input shaft wich turns the transmission gears AND the PTO gears. Thus the PTO shaft inside the trans is turning. If you depress the clutch pedal and disengage the clutch, the gears inside the trans are no longer turning. Now if you reach down with your left hand and move the PTO engagement lever on the side of the rear end you slide a coupling into place which connects the PTO inside the trans to the PTO shaft that is sticking out the back of the tractor. Now connect the driveline from the PTO shaft to the gear box on your bush hog. When you start the engine and release the clutch pedal engaging the clutch, the trans gears and the PTO gears start turning which results in simultaneous forward movement of your tractor and rotation of the PTO shaft. As the PTO spins you build up inertia in the spinning blades of the bush hog just like a flywheel builds inertia. As you are moving along you approach a fence, tree, house, whatever and you depress the clutch pedal and brake pedals expecting the tractor to stop but it DOES NOT STOP. Why does it keep moving forward? Because you have built up inertia in the spinning blades of your bush hog and now that inertia is travelling from the bush hog, back up through the driveline, into the PTO shaft and into the trans. Once inside the trans recall that the trans gears and the PTO gears are all interconnected. Now the PTO gears are driving the transmission gears and the inertia from the spinning bush hog is driving the rear wheels of your tractor and believe me your brakes are not strong enough to stop the tractor and thus the tractor runs through the fence, up the tree or through the side of the house. If you don't believe me take your tractor out into an open field where there is lots of clear area. Get the tractor and bush hog going and then depress the clutch pedal and watch what happens. If there were an obstacle or heaven forbid, a child, in front of you there is no way you can stop the tractor. That is why you need an ORC on your PTO. The ORC is a one-way ratchet that transfers rotation from the PTO to the driveline. If the driveline tries to turn the PTO the ORC rachets just as if you took a ratchet from your tool box and tried to turn it in the opposite direction. You need to know what size PTO shaft your tractor has, 1-1/8" or 1-3/8", before you can purchase an ORC. If you don't know which you have buy both ORC's before your next trip to the tractor and then return the one you don't need.

 

[Michaels Dad]

Since I'm not the sharpest knife in the drawer..my assumption sounds like what your explanation was.
Hit the brakes, and the overide ratchets and doesn't transfer energy to the wheels.....right?

 

[awhtx]

You are correct- the ORC ratchets or slips. In your previous post you mentioned a clutch slipping and I wrongly assumed you were speaking of the clutch between the engine and trans. Please accept my apology.

 

[Michaels Dad]

Apology not needed, and your explaination worthy of Pulizter prize.

 

[hzl6cm]

Its possible that your tractor already has the ORC installed. Just about every one the I looked at that was for sale in the last month already had the ORC with a 1 - 3/8-inch output shaft. One tip-off that it has an ORC is the presence of grease zirks in the housing that the splined shaft comes from.