PTO speed 8N early 1950 front mount

Ken-in-Ky · Jul 15, 2011

This thing is giving me fits!!!!!!!, today was the first day I have tried to run a 5ft bush hog on this tractor , The PTO wants to rotate at a hundred miles an hour ?????/, and seems horribly out of balance it shakes the bush hog as if its going to destroy it , can't seem to get low enough revs on the PTO shaft to make it run smoothly , looking for answers , would that indicate the PTO shaft bearing is kaput , It doesn;t sport a proofmeter so can;t tell engine revs but it does seem to be running high ,ie the hand throttle doesn;t reduce revs to an idle, Under load the engine needs more revs but that speeds the PTO and can't get a balance between forward speed and constant speed on the blades ,I know clear as mud , somehow there appears to be override on the hand throttle and the govenor is not compensating .I think I need an expert , I'm on this board because the answers come quicker.
Thanks.

DeltaRed · Jul 15, 2011

the rear pto is approxamately 540 rpm at full throttle.the "front"(off the crankshaft) is direct engine speed.

Fordfarmer · Jul 15, 2011

I'm more familiar with the '53 (jubilee) and later models, but... I think 540 PTO is actually about 2/3 throttle. It sounds as if you may have a Sherman auxiliary transmission (either an overdrive or a combo) which is increasing the PTO speed beyond what is needed or wanted. Does your tractor have a lever on the left side of the bellhousing?

BCnT · Jul 15, 2011

make sure your blades arent stuck on the stump jumper or for that matter make sure one isnt missing or broken...BLOCK UP YOUR MOWER BEFORE CRAWLING UNDER IT AND KILL ENGINE!
if that checks out disconnect the pto shaft and then engage the tractor pto to make sure its not internal on the tractor.

gene bender · Jul 15, 2011

Are you sure you dont have the tranny in overdrive. How fast does 1st gear travel with wide open throttle

old · Jul 15, 2011

Down lower is a forum just for the N series tractor and you might ask down there more people there that know the Ns. That said do you have a Sherman over drive transmission?? If you do then you could be up in over drive and that will spin the blades to fast. Or your blades could be stuck and not folding out or you could even have a blade missing. I lost a blade one time from under a brush hog. Never did find it and boy did it cause the hog to shake like crazy

paul · Jul 15, 2011

Do you have a Sherman tranny, and is it in the normal Ford speeds? This add on tranny affects pto speed as well as ground speed.

In normal tranny mode, the pto will go 540 rpm at close to full throttle. Try it in neutral, while not cutting anything. It can be difficult to spin up a 5 foot hog while also moving forward into fresh tall grass. Try it standing still.

Are the 2 blades in balance & free to swing, one isn't broken off a bit or something to make it unbalanced.

Any bearings on the gearbox, pto driveline, or even the tractor pto itself could cause you troubles - sounds like the tractor is new to you & haven't run anything ewlse with the pto?

Gears, too, on the gearbox of the hog could be bad.

A rather simple thing - is your pto shaft lined up right? The knockles on each end of the shaft need to be lined up. If you have a square shaft and put it together with one knuckle 1/4 off to the other, it will gnash & wobble & groan something terrible any time the pto shaft isn't perfectly straight. This would be the easy one?

--->Paul

OLD HECTOR · Jul 15, 2011

If ya cant get it figgured out you might check with Lyle, I think he might be lookin for a few more 8ns ,think he sold his last one [maybe thats the one you ended up with ,all junk]

Hobo,NC · Jul 15, 2011

To rule out the governor at about 1/4 throttle in neutral the gov should start to lower the RPM are lets say you should see it compensation... If the gov is not working right they will run wild and that makes it a beach to do anything with them...

I run all my N's with a hog at full throttle (1800 PPM) and no unusual vibrations... I never look at the proof meter anyways... just today i had to press another gov drive gear on one of My N's,,, it was slip'n on the gov shaft and letting the engine run away... The proff meter read zero when this happened :shock:

PTO speed 8N early 1950 front mount

Ken-in-Ky

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DeltaRed

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Fordfarmer

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BCnT

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gene bender

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old

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paul

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OLD HECTOR

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Hobo,NC

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