Clutch on Ztr

Discussion in 'Lawn Mowing' started by jathames, May 27, 2008.

  1. jathames

    jathames LawnSite Member
    Posts: 58

    Is it a big deal how many ft. lbs the clutch is rated on the ztr's?? I was noticing the scag tiger cub is 250 lbs... the toro 175 and the exmark 200... just wondering??:confused:
     
  2. bohiaa

    bohiaa LawnSite Fanatic
    Posts: 5,220

    Dont know for sure But I too would like to see some lab results on this issue,

    I would think it would be an issue if ya had helpers like mine who " NO MATTER HOW MANY TIMES I TELL HIM " enguage and dis. at full and some times idle,

    Thanks for posting
     
  3. mag360

    mag360 LawnSite Silver Member
    Posts: 2,446

    It's nice to have the extra strength in a component that is a real hassle to change out.
     
  4. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    It's just the clamping force. The friction material is usually the same. In other words...

    If it takes 5,000 cycles to wear out a Warner 175 pound clutch it will also take 5,000 cycles to wear out a Warner 250 pound clutch too.
     
  5. JimQ

    JimQ LawnSite Bronze Member
    Posts: 1,139

    Not necessarily true...

    The 175 lb clutch will slip and take longer to engage/brake than the 250 lb clutch.

    Bigger clutch equals less slip. That equals less friction material wear.

    Light clutches give an nice smooth feel when you engage the blades because they slip. Heavy clutches generally pull the engine down more when the blades are engaged but last longer.

    Q
     
  6. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    So which does "Q" prefer?
     
  7. JimQ

    JimQ LawnSite Bronze Member
    Posts: 1,139

    I'll take a heavy clutch on mine. In the same conditions, they last longer.

    Also, engage/dis-engage at 1/2 throttle, or as low an RPM as you can without the engine bucking/dying. It really does extend clutch life.

    Q
     
  8. bohiaa

    bohiaa LawnSite Fanatic
    Posts: 5,220

    Pls forgive me.... But what do you mean by cycles ?

    surely Not 5,000 time enguage/dis ?
     
  9. JimQ

    JimQ LawnSite Bronze Member
    Posts: 1,139

    Yep. 1 cycle = 1 engagement & 1 dis-engagement.

    5000 cycles isn't much. Our test requirements for a clutch range from about 16,000 for a consumer application clutch to as much as 90,000 for a commercial unit. This is at WOT with a simulated load on the blades.

    Q
     
  10. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    Then this begs the question....

    Why are there so many clutch failures long before either of those numbers in so many cases? I have a buddy of mine with a pair of Exmark Lazer Z's (I have a Dixie, it's not an issue) and he is putting clutches in at an average of 1,500 hours. Even at the 16,000 cycle number he would have to be cycling every 5.5 minutes. I can assure you that he is not. Every 15 minutes to 45 minutes is more the case. And they do attempt to keep the RPM's down when cycling.

    And at the 90,000 cycle mark he would have to cycle at under a minute.

    Even if you were to cycle ever 15 minutes the clutch should still last 22,500 hours. Huh?
     

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