640 bent PTO

grizz3000

Member
For those that don"t know yet, I"m a tractor newbie so be kind.

My 640 apparently has a bent PTO. I"m not sure if it"s the whole shaft, or just the "end" (sorry, don"t know the name of the piece you attach stuff to). It"s bent a good half inch+ off center. Unfortunately I can figure out how it happened. All I know is I attached my mowing deck to it and as soon as I engaged the PTO, the mowing deck drive shaft went crazy due to the PTO whirling instead of spinning on center.

Is this a handymans job? Could it be just a faulty PTO "end"?

I"m sure you all are going to say "pull the whole shaft and find out", but I guees I just need to hear it before I get the nerve to tear it apart.

I bought a PTO clutch awhile back. I took off the old PTO end to find out the new clutch wouldn"t fit into the the tractors" PTO fitting. (the bottom rim of the new clutch was ever-so too tall to make it fit to the shaft pin hole)

I"ll run it without a clutch on the shaft to see if the shaft spins on center. But gosh, why doesn"t that new PTO clutch fit down into there?
 
When you talk about shaft 'end' and PTO 'clutch' I assume that you are refering to a 1-1/8" to 1-3/8" adapter as the 'end' and the clutch is simply an over running clutch (ORC).
Those long adapters ARE sloppy and will behave like you're describing.
What I'd do is remove the adapter from the shaft, then put the PTO in gear and observe it for out of round. You should easily see it if it's bent...
If you find that it is bent or even if the splines are poor on the shaft, then replace it. Heck, if you have a 1-1/8" shaft in it now and have no particular need of the 1-1/8" shaft, get rid of it in favor of the 1-3/8". The small shaft was a holdout from another Eon when belt pulleys were still common. 1-3/8" 6 spline has been 'the standard' 540 rpm PTO for handy 50 years... Beyond that, if the hog is the only PTO attachment that you use or the only one that requires the ORC, then I would incorporate the ORC into the mower shaft. You replace the splined yolk that attaches to the tractor with and ORC yolk. Personally I'd do that on every machine that required the ORC. This shortens and stiffens the driveline, eliminating most of the symptoms you have.

Rod
 
Good evening Grizz,

I'm a newbie as well. From what I have read here (never done it or seen it first hand), the end you are referring to is exactly that, the end of a splined shaft. As you feared, you likely need to pull the shaft and take a look. A half an inch off center seems huge. Is this the first time you've tried the PTO?

On the BRIGHT side, as I've read here, it doesn't sound like a bad job. Some fellas have even posted about parking the tractor facing down a steep hill or with the front end in a ditch to avoid losing fluid. They usually indicate it is only held in by 4 bolts and should be easily removed. Those with first hand experience will direct you better, but I wanted to encourage you, it shouldn't be a bad job as far as turning the wrenches goes. :D :D

640PTOshaft.gif




Best of Luck,

Chris
 
My Fergie..My pto has a bearing there with an oil seal,if yours is similar then put the front wheels in a ditch and the oil may drain forward without having to drain,
 
i agree with Rod.. pull your ORC off and look at the bare pto shaft to look for a bend... if it is bent.. go ahead and repalce the entire bearing carrier/seal assembly, as if the shft is bent.. the bearing may be damaged too.

it's a 4-bolt job.. but you will likely need to drain your fluid unless you are running UTF in all the sumps.

On the hundred series tractors, the pto shaft rides thru a seal that seperates sumps.. unlike the 8n and older fergies that are open sump, which lets you park nose down into a ditch to save your oil.

soundguy
 
just a warning....watch out for crap that is in your way when you pull the shaft...my tractor has a 2" ball attached for pulling my trailer...when I yanked my PTO shaft after a mishap with the bush hog and an "invisible" tree stump...my thumb wound up between the end of the shaft and the ball.....not pretty at all...I did make up some new words though....good luck
 
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