Timing Mower Blades

Discussion in 'Mechanic and Repair' started by Daner, Mar 24, 2006.

  1. Daner

    Daner LawnSite Bronze Member
    Posts: 1,307

    I have a 42" dual blade deck...JD and the blades are out of time again
    To my understanding the blades should be at 90 degree angels from each other...I,m i right about this??
    I noticed it when i was leaving a strip of grass in the center of the deck
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    I'm not as familiar with Deer Products but if it has a V type belt there is no such thing as timing the blades. Check the blade tips for wear, That will cause streaking.
     
  3. fly-4-fun

    fly-4-fun LawnSite Member
    Posts: 0

    I've got one of those 42" decks that is a mulching type deck on a SST16 JD.
    You've got to have those timed at 90 degrees from each other or they will hit because the blades are the same length. If yours has the cog style drive belt for the spindles, you can and should time them at 90 degrees from each other.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Thanks fly-4-fun, For enlightening me on the Deer timed deck as I said I don't work on too many Deer's.
     
  5. Daner

    Daner LawnSite Bronze Member
    Posts: 1,307

    Its a John Deere lt-166...And yes it has the cog style Belt drive...There was one time that i hit a good sized branch and it sent the blades to hit each other.
    Now the one blade is say 20 degrees off of being perpendicular from the other/
    The other mowers that have the v belts...Should they not be in the same 90 degree from each other??
     
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    No, It's not necessary because the V belt type units have the spindles mounted in the deck where the blades wont hit each other.
     
  7. Daner

    Daner LawnSite Bronze Member
    Posts: 1,307

    Thanks Rob...So if you have say 3 blades...with the v belt and all the blades are inline with each other you will get the same quality cut??
    I understand that the v belt can slip from minor hits...but shouldn't they be install in a tip away from each other pattern??
     
  8. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    The blades have such a close tolerance tip to tip on a V belt deck that it makes no difference where they are positioned, On a 3 blade deck the center spindle is forward of the two outer spindles. So for that reason you still get a quality cut. Most all commercial units use a V belt and have a good quality cut. Myself I wouldn't own a timed deck for the problem you have right now and the cost of a timing belt is double or more in price over a standard V belt and all over hitting a small stick !
     
  9. fly-4-fun

    fly-4-fun LawnSite Member
    Posts: 0

    My mower has a heavy spring that keeps tension on the cog belt that drives the
    blades. If you don't have the correct tension on the belt, it will allow the blades to get out of time when you hit a small object, so the correct tension is very important on these timed blade decks. I tried to look up your mower on the JD parts site to see if it was like mine, but couldn't find one with a number like you said yours was, Daner. Also, like Rob said, if the blades are worn on the tips, they will leave a streak down the middle of the deck.:waving:
     
  10. Daner

    Daner LawnSite Bronze Member
    Posts: 1,307

    The blades are almost new...and they are not worn on the tips...But this gurl has the same as yours...the spring tensioner...Its a freedom mulch Deck...LOL
    That gives me no freedom...well i guess i have to take off that plastic piece on the top ...back off the spring and get those blades on a 90
    Certainly appreciate all your help guys:waving:
     

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