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Hi Guys,

I've been lurking at the forum reading and learning for a couple of years and now I have a reason to make my first post. I'm having problems with my front PTO on my recently purchased JD 318. Here's why I"m posting:

1. Sometimes when I flip the switch the PTO comes on and the mower engages and sometimes the PTO doesn't come on I can't seem to figure out any pattern as to why??? Is there a certain position the hydro tranny, brakes, throttle and hydraulic lift must be in for the PTO to operate? I've tried every combination I can think of and can't seem to find a pattern to the operation of the PTO. Sometimes it works and sometimes it doesn't. As an FYI before I installed the mule drive and mower deck the battery light was nearly always on during tractor operation. I gave the battery a good charge and the light went out for a little while and then came back on and is now on again all of the time.

2. When the PTO did kick in I did some test mowing for about twenty minutes to see how the mower cut (great) and fiddle with the hydraulic lift and what not. Toward the end of the test cut I could hear the engine bog down and the oil light came on. It sounded to me like the engine was overheating and might sieze due to an unusual strain. I was concerned the pulley at the front of the motor that drives the belt might not be a "free" as it should be. I knew I had plenty of engine oil because I check that before I operate the tractor and indeed the engine oil was fine. What could be causing the over heating?

I did find one thread where somebody else's PTO would work when the engine was cold but not once it was warm and that problem was apparently caused by worn windings in the PTO magneto which was corrected by replacing the PTO. My PTO seems to be working or not working at random despite weather the tractor engine is warm or hot. Bad windings might explain question number 1 but I don't think it would explain question number two.

Any thoughts on this would be much appreciated.

For background info you should know I just installed the mower deck and mule drive over the weekend for the first time. No wonder it's called a mule drive - what a pain in the ***!!!!

Prior to installing the deck and mule drive I inspected all of the components. The pulleys on the mule drive were turning free and I greased the fitting and sprayed both pulley bushings with some WD 40 and then a bit of grease so the mule drive pulleys were turning free and easy with no slop.

I inspected the mower deck and each of the mower blades was turning free and easy with no slop. Surprisingly, when I removed the mower deck covers I couldn't find any grease fittings but it was turning free and easy.

I did inspect the pulley at the front of the engine and that was not turning free and easy. I sprayed the base with a bit of WD 40 and figured that pulley was not turning because of engine compression. Maybe I'm wrong and that pulley is supposed to be turning free and easy as well.

Any help with problems number 1 and 2 would be greatly appreciated. Thanks in advance guys.
 

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The Magnificent
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Hi Guys,

1. Sometimes when I flip the switch the PTO comes on and the mower engages and sometimes the PTO doesn't come on I can't seem to figure out any pattern as to why??? Is there a certain position the hydro tranny, brakes, throttle and hydraulic lift must be in for the PTO to operate? I've tried every combination I can think of and can't seem to find a pattern to the operation of the PTO. Sometimes it works and sometimes it doesn't. As an FYI before I installed the mule drive and mower deck the battery light was nearly always on during tractor operation. I gave the battery a good charge and the light went out for a little while and then came back on and is now on again all of the time.
Two thing to check here. First is the air gap on the clutch, and second is the seat safety switch. Member Stash just posted a very detailed adjustment procedure within the last week or so.

"Adjusting the air gap on the PTO clutch to 0.018" when the unit is cool, should do the trick unless the clutch or PTO switch is going bad. The clutch has three spring-loaded adjustment nuts. Beside each nut is a slot. Slip an 0.018" feeler gage into one of the slots and adjust the adjacent nut to affect a slight drag on the gage. Go to the next nut and slot and repeat. Several adjustments at each location are necessary to fine tune the gap, because when you adjust one nut it affects the other two."

I found my intermittent operation was due to my seat safety switch being broken.

2. When the PTO did kick in I did some test mowing for about twenty minutes to see how the mower cut (great) and fiddle with the hydraulic lift and what not. Toward the end of the test cut I could hear the engine bog down and the oil light came on. It sounded to me like the engine was overheating and might sieze due to an unusual strain. I was concerned the pulley at the front of the motor that drives the belt might not be a "free" as it should be. I knew I had plenty of engine oil because I check that before I operate the tractor and indeed the engine oil was fine. What could be causing the over heating?
If the engine nearly stalled, you might have seen the oil light. When it bogged down were you in particularly high grass?
Have you inspected the deck to see if all your spindles still turn freely?
Is the deck clooged perhaps a rope that you didn't see and mowed over?
If it's truly overheating are your cooling fins and oil cooler clean?

No wonder it's called a mule drive - what a pain in the ***!!!!
This begs me to ask if your belt is indeed routed correctly. The mule drive is something new for many, but it isn't in my opinion extremely difficult.

I wouldn't spray WD-40 on the PTO clutch. The front pulley should not turn freely with the engine off.

As for your alternator light have you measured the voltage from your regulator?

Hope this helps - keep us posted.
 

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This might sound stupid, but check the contacts in your plug wires. Some of the issues you describe are similar to ones that I had a few summers back. It turned out that contacts in the plug wires were rusty!
 

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Citizen of Earth
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I would also check your battery and charging system, ground wire connections, battery cable condition and connections, because the battery light shouldn't be lit all the time. I'm thinking that you are using more electricity than the motor is making and the bogging down of the motor you heard was the ignition system being slowly starved for electricity to keep running and power the PTO at the same time. When you charged up the battery, the light went out, but I think the battery is not being recharged properly if at all, and as the battery drains while powering the PTO and ignition, your problem occurs
 

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JD318
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"battery light was nearly always on during tractor operation"

What Joe said above.....You need to get this fixed first. Battery voltage s/b around 13.5-14v at the battery when running.
 

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While mowing today I turned off the PTO, with engine still running, on my # 2 JD 318 to talk to my wife. When I turned the switch back on the dash light came on but not the PTO so I could not finish mowing. I tried several times with no better results. Later, after finish mowing with my other, exactly same #1 JD 318, I tried again and it worked fine several times. I know it is NOT the seat switch! I am wondering if there might be something related to heat that caused it not to work. Any ideas or suggestions would be greatly appreciated.

By the way, I do not see the "Post new thread" icon anywhere so I am jumping in here. It used to be in the upper left, I think, but is now missing?
 

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If you haven't checked the air gap that was referred to in D-Doggs post then you should do that.
 

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Thanks for your reply. I looked at the video. I'll check the gaps tomorrow. Hopefully that will solve the problem. I need to get a repair manual for the 318's since I have two now. The owners manual is pretty basic. Where is a good place to get a repair manual?
 

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Thanks for your reply. I looked at the video. I'll check the gaps tomorrow. Hopefully that will solve the problem. I need to get a repair manual for the 318's since I have two now. The owners manual is pretty basic. Where is a good place to get a repair manual?
Your local JD Dealer should have one or he can order one for you........... I would get the CD Version. That way you can print out what you need to work on.............KJD
 

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HD
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I've adjusted my air gap and on occasion still have an issue with the PTO sometimes not engaging after I had been mowing for a while. A quick fix though, I flip the PTO switch, and then do a quick/jerk into reverse. That seems to do the trick and get the PTO to engage. The trick doesn't work going forward though, and prior to adjusting the air gap, nothing would work but letting it cool down. Probably have grooves that need machining down or readjusting the gap, but this is working.
 

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Three of my friends
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Heres an issue that needs to be addressed on these pto clutches.I was looking at my 332 clutch and realized that when we set the .018 gap that we are setting this narrow gap between a movable part ( rotor) and a stationary part( armature),it occured to me that if the rotor wasent setting all the way back against the bushing it contacts that the gap COULD be too large and not really .018,i think that in order to really get the gap right one needs to assure the rotor is actually back toward the engine as far as it will go,a thin screwdriver pressed into the slot where we set the gap and pry the rotor back would do the job.Most likely 99% of the time all would fine but 1 time of not being back would drive one to drinking and the rotor needs to be free to move forward and aft on the crank to make the .018 work like it should.
 

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Three of my friends
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HDmstng,your issue might be a sticking rotor and reversing would force the rotor forward in order to contact the armature,dosent take long to remove the front and check for seized rotor,if its stuck you would have a hard time pulling it off.
 

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HD
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HDmstng,your issue might be a sticking rotor and reversing would force the rotor forward in order to contact the armature,dosent take long to remove the front and check for seized rotor,if its stuck you would have a hard time pulling it off.
Thanks for the tip biker!
 

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I had a similar problem with a 318 PTO and one of things that I found out was that when you are adjusting the three spring bolts that you have to go back and forth around the three after you adjust each one. You cannot just adjust each one at .018 and be done. Everytime you move one the other two move in relation to that one. Another thing that you can try is to rig up a jumper wire with alligator clips on each end and jump the PTO wire directly to the battery. You would only need to do this if while you are mowing the PTO will not re-engage. Then you can simply clamp the wire from the battery to the PTO and see if it will work. If it does then you have a safety switch problem or an intermittent contact somewhere. One other thing is that if the PTO friction plate heats up while you are using it then the gap you set might not be enough to keep the clutch working properly. I mean that if the clutch is slipping too much then the coil can break down from excess heat and will stop working.Good luck!
 
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