pto clutch

Discussion in 'Mechanic and Repair' started by WhitakerServices, Aug 24, 2007.

  1. WhitakerServices

    WhitakerServices LawnSite Member
    Posts: 159

    I am running a Toro wb and today my pto stopped engaging. I have tested and jumped the switches and everything checks out with 6 volts. I have confirmed voltage through the whole length of the circuit all the way up to the wires coming out of the pto. I checked and set the air gap to .015, and the clutch looks fine ( no metal to metal, not worn out ) I have never had a pto clutch go out electrically it has always been a mechanical wear issue. My next step is to trace all the wires to ensure nothing is grounding out and clean the connections. Should I use di electric grease on the connections? Is there anything else anyone can think of that may help? Is 6v the normal voltage?
    Please help
    thanks in advance
    Russ
     
  2. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 923

    "Is 6v the normal voltage?"
    Not if you have a 12V system!
    Disconnect the connector and measure the V coming FROM the supply.
    Also measure the resistance of the PTO itself.
    Sounds like it may have shorted some windings??
     
  3. WhitakerServices

    WhitakerServices LawnSite Member
    Posts: 159

    just took a voltage reading before the fuseable link ( right before the connection to the pto) It is reading 19-20 volts I guess that explains why my 7amp fuse keeps blowing. I could have sworn it read 6 when I read it in the field. Does any one know what voltage the pto clutch requires?
     
  4. mattfromNY

    mattfromNY LawnSite Bronze Member
    Posts: 1,581

    My ferris had a similar problem last week. Plenty of voltage before the fuse, then dropped at the other side of the fuse. Fuse wasn't blown, but maybe got wet, b/c the end of the fuse holder itself was burnt. Replaced the fuse holder (fusable link?), and got the correct voltage.
     
  5. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 923

    ASSuming you have a 12V system, the PTO would start "dropping out" when the V gets somewhere below 12V. Probably 10-11??? Just guessing here.

    What scale do you have your meter on? AC or DC?
    The fact you say you read 19-20V, makes me wonder if the diode/regulator in your charging system is shorted out and you are passing AC only??
     
  6. WhitakerServices

    WhitakerServices LawnSite Member
    Posts: 159

    my voltmeter was set to dc.
     
  7. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 923

    Max DCV you should read would be around 14+.
    Since AC basically alternates between + & -, I wonder if your regulator/diode just might be shorted?
    The Alternator puts out something like 28-40 ACV. A typical diode just lets the + pulse pass through, thus converting it to a "pulsating" DCV.
    IF it's allowing the - part through, that would work against the DC+.
    What I would do-
    1. With engine OFF, jumper 12V direct from the battery to the PTO and listen for a CLICK.
    IF it clicks "normally", then measure the current draw. That should be about 4 amps.
    IF everything above seems to check out OK then I would think there is something "going on" in the charging system.
    There are only 3 things I can think of that would give you a 20V reading-
    Bad charge system
    Bad meter
    Operator error
     
  8. WhitakerServices

    WhitakerServices LawnSite Member
    Posts: 159

    the mower is a pull start but I guess I can jumper from a car battery without damaging anything?

    Thanks for the replies
     
  9. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 923

    The fact it's not electric start & no battery tends to make me think your charge diode is the culprit. That would explain the 20V reading.

    Before jumping the battery, read the V at the PTO again, using BOTH AC &DC scales. Shouldn't be anything on the AC.

    What are the engine#'s?
     
  10. WhitakerServices

    WhitakerServices LawnSite Member
    Posts: 159

    it is a Kohler cv14t
    spec 1412
    family skh398u1g2rb
    thanks again for all your help Bill

    Russ
     

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