Slipping alternator belt on 86' Testarossa | FerrariChat
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Slipping alternator belt on 86' Testarossa

Discussion in 'Technical Q&A' started by kogmachine, Aug 5, 2016.

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  1. kogmachine

    kogmachine Rookie

    Aug 5, 2016
    5
    #1 kogmachine, Aug 5, 2016
    I had my alternator rebuilt because the battery was draining. The guy who rebuilt my alternator told me that only the bearings needed replacing. I ordered new belts but when they arrived they were the wrong belts. The old belts looked fairly new so I reused them. Everything went back together easily, but the belt howls now. I have the belt cranked so tightly that I'm worried the alternator bearings will quickly wear out again. I've identified that the (serpentine) alternator belt is the source of the noise. Any advice that will help me resolve this problem will be greatly appreciated. Thank you!
     
  2. Jeff Pintler

    Jeff Pintler Formula Junior

    Jul 20, 2005
    537
    Richland
    Full Name:
    Jeff Pintler
    #2 Jeff Pintler, Aug 6, 2016
    Just posted a solution to this problem in the TR section under "alt. rpm".

    Jeff
     
  3. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,932
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #3 Steve Magnusson, Aug 6, 2016
    So you have the upgrade to the later flat multi-rib belt design installed, and are still having trouble? Many reports of trouble with the original v-belt design like Jeff indicated, but can't recall a single previous report of trouble with the later multi-rib design. Is that what you are calling "serpentine"?
     
  4. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,996
    Isle of man- uk
    #4 mike32, Aug 6, 2016
    Assuming this is a flat grooved belt, similar to that on a 430. If you have it that tight and it is making a noise, does it have an idler to tension the belt ? If so is it the belt or the idler bearing making the noise,
    You can normally feel a bit of twist in them on the longest run so it should not be too tight. Otherwise try a light spray of WD40 on the running side, my Mondial belt on the ac used to howl at times and wd 40 used to stop it.
     
  5. kogmachine

    kogmachine Rookie

    Aug 5, 2016
    5
    #5 kogmachine, Aug 9, 2016
    Yes Steve, the serpentine belt is a multi ribbed design.

    Mike32, I tried wd 40 and it quieted the belt for a minute but then the howling came back. As far as I know there is no idler to tension the belt, and the alternator itself is the tensioner.

    I will take a look at Jeff's post, and hopefully there's some useful information in it that can help me.

    Thanks for your help guys, and if you can think of anything else that might help please let me know.
     
  6. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,996
    Isle of man- uk
    #6 mike32, Aug 10, 2016
    Thinking about it, is it the ac compressor that does the tension- why not just change the belt as you know the wd 40 shuts it up for a while, so its not an idler bearing. As it is the old one it is probably past its best.
    It looks like it has idlers to change the belt direction
    Dont be too tight when setting it, but use its longest run and see if it will twist - i use about 1/4 turn
     
  7. kogmachine

    kogmachine Rookie

    Aug 5, 2016
    5
    #7 kogmachine, Aug 10, 2016
    Thanks again Mike32, I ordered a new belt but was sent the wrong one. I placed another order for what I hope is the right belt and I should have it soon. I'll keep you posted and let you know if I make any progress. I'll check out the a/c compressor as well.
     

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