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Discussion Starter · #1 ·
Hi all. I’m stinky. It’s an underwear changing thing thank you. My other issue is my jd stx 38 pto switch. After many years of mowing and no problems the blades began to hesitate to engage maybe about 5 to 10 seconds after switch was pulled. This happened maybe 4 or 5 times. The next time I pulled pto switch the blades wouldn’t engage I replaced the pto switch and the blades engaged immediately however this lasted a minute or two then the new switch melted the pull knob. My deck is black and all pulleys and blades turn easily. I mentioned the timing difference between when I pulled the pto switch and the blades engaging yo hopefully give someone smarter than mea clue as to what may be the issue. I am thinking it is the pto clutch I am pretty dangerous with a screwdriver in my hands so could you please explain possible causes and remedies in terms that a fish would be able to understand? Ok maybe a clam. I wait patiently for your words of wisdom

love. Stinkybritches
 

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Sounds like a short somewhere to me...if you aren't very good with tools it might be better handled by a professional
 

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Resident John Deere Tech
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given the age of your machine, i would dare say the PTO windings have given up the ghost. this will cause high current thru everything, causing the melted switch.
 

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Resident John Deere Tech
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@bogieboy...would adjusting the pto help at all do you think?
i am gonna say no, just off the fact that its melting the switch, i am gonna say it needs a PTO replacement... the definitive answer would be putting a volt meter on it set to ohms, unplug the clutch from the tractor and measure the resistance of the clutch, from one terminal to the other, and also each terminal to ground. if it is lower than 3 ohms between the terminals, its bad. if it shows any continuity from either terminal to the body of the clutch, again, bad.

typically if it is just that the pto is out of adjustment, once the coil warms up, you loose a bit of magnetic field, and it drops the clutch disc off the rotor, causing the pto to "shut off" but that (in my experience) does not melt the switch, as the good coil even warm will pull right around 5-7amps. if it has shorted out, your resistance lowers, and causes the amps to spike, either blowing a fuse, or melting the switch.
 

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The clutch coil works against a sizeable spring
The wider the clutch gap the more energy ( read amps ) the coil draws to keep the plates together
Amps = heat
 

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Resident John Deere Tech
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The clutch coil works against a sizeable spring
The wider the clutch gap the more energy ( read amps ) the coil draws to keep the plates together
Amps = heat
Bert i have seen clutches with 40 to 50 thousandths of clearance function perfectly fine and not burn out the switch. I work on these things for a living... i see plenty of them...LOL
 

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By itself may or may not get hot enough
I have come across some drawing near double the scheduled current.
Add some corrosion or a bad ground or a broken wire arcing or a bad voltage regulator.
Or any combination of the above .
As you know it all adds up

Just finished a Z 225 a few weeks back .
Totally melted the fuse & fuse holder to the point that the wire pulled out with the fuse.
There was no short circuits, just a ground wire without any nut continually arcing .
And the full business name is Berts Mobile Mower Repairs so guess what puts the bread on my table ?
It just depends upon how long power is passing through the circuit .
In this case the owner mowed her 3 acre yard then went on and did 5 more on her dad's place down the street and at this time of the year, twice a week + about 3 to 4 acres of council bush park behind both properties.
 

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Discussion Starter · #10 ·
Stinkybritches here and want to thank all new best buddies who have replied to my thread. You guys are great. If stinky was not Jewish I would be getting all of you many Christmas presents and much Thanksgiving sex. Stinky has now removed pto clutch and finds that clutch locks up occasionally when I spin it. I hope this is a sign that issue was diagnosed correctly. I have placed an order for a new clutch from John Deere. My next question is on the clutch I took off it appears there is a spacer at the top of the clutch. Does this spacer come off and if so how? After I get past this how do I reattach new clutch to tractor if motor spins while I am screwing bolt back into clutch? Once again thank you all for help. I will try and attach picture of spacer that is on top of clutch.
2480121
 

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A common method for preventing the motor from turning is to remove a spark plug, and feed in a length of rope, leaving some of the rope hanging out so you can pull the rope out after you are done. You may wish to disconnect the battery to make sure you don't accidentally try turning the engine over with the rope still in the cylinder, as that can result in damage to the engine.

I don't know about your spacer, it might come with the replacement PTO, it might need to be hammered/pressed out and then hammered/pressed into the replacement.
 

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Resident John Deere Tech
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according to the parts breakdown, it is a separate part, can you get a punch or screw driver on the edge of it in the bore of the clutch, and then tap it out with a hammer?

2480190


as far as locking the crank, the rope trick works well, as previously mentioned.
 
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