How do I loosen the drive belt a little?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by yibo829, Mar 23, 2013.

  1. yibo829

    yibo829 Junior Member

    Joined:
    Jan 11, 2012
    84
    5
    0
    Location:
    Florida
    Vehicle:
    2009 Prius
    I think the dealership tightened the drive belt too much, how do I loosen it a little bit?
    Do I just loosen the tensioner bolt a little?

    Thanks for your help!
     
    #1 yibo829, Mar 23, 2013
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,470
    6,876
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    There is a serpentine belt running the water pump.
     
    #2 JimboPalmer, Mar 23, 2013
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,491
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    It is necessary to first loosen the nut on the idler pulley, then you can adjust the tensioner bolt. Tightening torque on the idler pulley nut is 30 ft.-lb.

    Since you needed to ask the question about how to adjust the serpentine drive belt tension, I am wondering whether you have correctly assessed that it is too loose. If you exert around 22 lb force on the longest run of the belt between the crankshaft pulley and the idler pulley, it should deflect 0.5 in.
     
    #3 Patrick Wong, Mar 23, 2013
    yibo829 likes this.
  4. yibo829

    yibo829 Junior Member

    Joined:
    Jan 11, 2012
    84
    5
    0
    Location:
    Florida
    Vehicle:
    2009 Prius
    Thanks Patrick. Now that I think about it, I probably did not correctly assess that it is too tight, since I certainly did not apply 22 lbs of force to the drive belt to see its deflection. So I'll just leave it as it is.
    I'm almost at 70,000 miles and the dealership people told me my drive belt was making noises so I let them changed it, I don't even know if it is really making noises though.
     
    #4 yibo829, Mar 23, 2013
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,491
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Well, whether it was making noise or not, it is highly likely that the belt had developed lots of cracking given that odometer reading, so it was reasonable to replace the belt.
     
    #5 Patrick Wong, Mar 23, 2013
(You must log in or sign up to post here.)