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Hot!PTO Assess Rebuild

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backporch
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2019/04/09 23:13:32 (permalink)
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PTO Assess Rebuild

I had posted in another thread all the difficulty I was having getting a B&S 18.5 HP Intek motor to crank past compression.  The problem kind of fixed itself and now it cranks nicely and even starts.  I did get some smoke coming from the front of the motor and I believe it is the PTO.  It is possible that it was not adjusted correctly and could also have contributed to starting issues.
 
Since I probably decreased its life significantly in the little while it ran, is there a way to verify it still might work and possibly clean it up and replace the friction surface?  I think backing off the adjustment nuts may have gone a long way toward making it work, but I decided to remove it and hopefully clean it up and make it usable again.  Any suggestion on PTO evaluation, maintenance?
 
PTO is part# 180505.

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    Mikel1
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    Re: PTO Assess Rebuild 2019/04/10 12:37:20 (permalink)
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    You sure it was the electric clutch smoking? Don't see how it could have affected starting unless the bearing seized.
    Other than adjusting the gap, no other maintenance required
    backporch
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    Re: PTO Assess Rebuild 2019/04/10 13:44:11 (permalink)
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    Thanks Mikel1.  I can't say for sure it was the clutch, but it smelled like brake dust. 
    I did notice later looking at the clutch that the part of it that should spin freely was rubbing alot.  backing off the adjusting nuts let it move freely.   I guess I will do the adjustment and reinstall.   If I can go at least long enough to test that the tractor moves and cuts grass, I don't mind replacing it during the season with a new one.
    AVB
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    Re: PTO Assess Rebuild 2019/04/10 13:54:33 (permalink)
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    Check the PTO coil resistance. It should be 1.7 ohms [Ogura clutches have 3-4 ohms resistance] or higher. Anything under 1.7 ohms [Warner] either a partially or fully shorted PTO coil.  The maximum amp should be no more 5-7 [about 3-5 amps for Ogura] amps depending on the PTO coil. I have seen partially shorted PTO clutches to draw over 16 amps and still work but drain the battery as the alternator can't keep up with the drain.
     
    As far to clutch it is non serviceable except for the air gap adjustment. You can't even replace a bad bearing. Now the aftermarket Xtreme PTO clutches do have replaceable bearings. These PTOs also has two bearings one next to the engine that operated 100% of the time and the other one which is operated when the clutch is disengaged. This bearing is the one that usually fails leading the deck trying to turn while you trying to start the engine.
    backporch
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    Re: PTO Assess Rebuild 2019/04/10 14:33:45 (permalink)
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    Good info AVB.  I did see the Xtreme clutches for sale.  
     
    I don't have any bearing issues.  Air gap is most definitely not right.
    AVB
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    Re: PTO Assess Rebuild 2019/04/10 17:09:32 (permalink)
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    backporch
    Good info AVB.  I did see the Xtreme clutches for sale.  
     
    I don't have any bearing issues.  Air gap is most definitely not right.



    Here is the adjustment info per Ogura.

    Step 1

    Mount all components to the clutch according to our installation procedure. Please make sure that the brake plate and coil springs are in the proper position. Start to tighten down the gap adjustment nuts. The same number of turns should be applied to each nut successively so the adjustment is as even as possible.

    Step 2

    There are three inspection slots on the brake cover. With a feeler gauge of between .013-.015 for clutches used on 25 horsepower and under, and .015-.022 for clutches used on 25-31 horsepower, tighten each nut down until slight contact is felt on the feeler gauge. Once all three are finished, go back and check the air gap (occasionally some minor adjustment will be required).

    Step 3

    Once the air gap is within the specified range, engage the clutch at full coil voltage and rotate it. If there is no contact on the brake shroud, the clutch is okay; however, if there is any contact with the brake shroud, the gap adjustment nuts should be backed off slightly to eliminate the contact.
    post edited by AVB - 2019/04/10 17:15:22
    backporch
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    Re: PTO Assess Rebuild 2019/04/13 11:43:47 (permalink)
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    I have adjusted the clutch and reinstalled. 
     
     
    I can see that the part of the clutch that spins with the shaft is not rubbing or binding with the stationary part. If there is no binding with the clutch harness disconnected, is it OK to start up the mower and run that way?  I was hoping to initially check the motor and transmission before testing/engaging the clutch.   I also don't have the mower deck or belt for the blades connected.
     
    I also want to rule out the smoke that I experienced from being anything besides the clutch
    AVB
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    Re: PTO Assess Rebuild 2019/04/13 12:07:54 (permalink)
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    Just make sure that the anti-rotation device is in place so that the stationary part of the PTO clutch doesn't go spinning and pull the wiring harness out the of the PTO clutch assembly when you start up the mower's engine.
     
    Those PTO clutches with permanently mounted wires are destroyed this way. This can be a costly mistake.
    backporch
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    Re: PTO Assess Rebuild 2019/04/16 09:57:18 (permalink)
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    OK.  PTO adjusted and mower running well.   I didn't have the nerve to engage the PTO last night while I had the mower out for a quick test ride, but I did check that it engages without contacting the stationary part of the PTO with 12v applied.  Resistance value was good.
     
    Smoke that I noticed was from the exhaust.  Must have gotten some oil on it.
     
    If the PTO does have issues at this point when engaged, I will replace it.  At least I now have a mower with a working motor and transmission.
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