I don't understand the tensioner setting instructions | FerrariChat
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I don't understand the tensioner setting instructions

Discussion in '348/355' started by carwhisperer, Dec 19, 2015.

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  1. carwhisperer

    carwhisperer Formula Junior

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    #1 carwhisperer, Dec 19, 2015
    Page 62 of the factory WSM

    Stretch the belts as follows: Lever in holes 3 and 4 on the belt stretching bearing. Rotate towards the engine inner side until the catch 5 is free to slide in its housing, then lock bolt 1. Let the engine run for some minutes and check: the distance 6 on the mule guide should be ~ 2.5mm and catch 5 free to slide.

    I'm working on the US passenger side right now.

    Lever in holes 3 and 4, easy to understand. Rotate "towards" the engine inner side? It seems to make sense to rotate it away, i.e., clockwise, which moves the tensioner roller away from the engine centerline. Otherwise, you'd have to go over center and the roller would be really close to the cam, which is not how it looks on the disassembled driver's side.

    Also, I get the 2.5mm part but how do you know how much force to put on the hole 3 and 4 lever?
     
  2. Dave rocks

    Dave rocks F1 World Champ
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    #2 Dave rocks, Dec 19, 2015
    We could help you more if you told us what you are doing? Major? Changing belts? Changing tensioner bearings only?
     
  3. yelcab

    yelcab F1 World Champ
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    #3 yelcab, Dec 19, 2015
    It is better if you read Italian. Otherwise, this is what they are trying to say.

    Install the belt
    Compress the tensioner and put a pin into the hole to keep it in compressed position
    Install the tensioner and tensioner bearing
    Rotate the tensioner bearing to compress the tensioner such that you can slide the "pin" in and out easily.
    Lock down the tensioner bearing bolt

    Repeat on the other bank.

    Rotate the engine by hand two revolutions.

    Ensure the pins are still sliding in and out easily. Then remove them.
     
  4. taz355

    taz355 F1 Veteran
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    #4 taz355, Dec 19, 2015
    In Italian it says Viva Ferrari
     
  5. carwhisperer

    carwhisperer Formula Junior

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    #5 carwhisperer, Dec 19, 2015
     
  6. SoCal1

    SoCal1 F1 Veteran
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    #6 SoCal1, Dec 19, 2015
    Stanza vostro stomaco mentre si gira in un cerchio

    :)
     
  7. carwhisperer

    carwhisperer Formula Junior

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    #7 carwhisperer, Dec 20, 2015
    :)

    OK a couple more questions now that I had a chance to think about it.

    1. Do the arms upon which the rollers mount pivot a little bit on there rubber bushings during operation? I guess they must, otherwise there would be no need for the tensioner/dampeners.


    2. Where do you position the arms? Are they supposed to be down as far as they will go before you set the tension with the pin and/or 2.5mm gap?
     
  8. Andy 355

    Andy 355 Formula Junior

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    #8 Andy 355, Dec 20, 2015
    Ok so you are doing a belt change.. Make sure the lower drive gears have at least 3 spot welds to both faces to ensure the fences stay put. Also replace the tensioners and use hill bearings for the rollers. Wait till you have to dial the cams,thats fun too!! These things are not made of glass but some of it is a bit tricky if its your first dance.. Good luck and keep us posted. :)
     
  9. cf355

    cf355 F1 Rookie

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    #9 cf355, Dec 20, 2015
    perfect translation
     
  10. gobble

    gobble Formula 3
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    #10 gobble, Dec 20, 2015
    I didn't think it was that simple. I read somewhere, and I think it was written by Brian, and my mechanic agreed, that the pins were there just to set things for install but once the belts were on you needed to adjust the tensioner gap to a spec in the WSM. If you just tightened where the pins slide in and out the gap isn't wide enough and the parts (I'm being very technical) would bang against each other and basically the tensioners wouldn't do what they're supposed to do.
     
  11. cf355

    cf355 F1 Rookie

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    #11 cf355, Dec 20, 2015
    yes the gap is checked...you use needle nose pliers in the 2 slots for the final check/adjustment.
    good point.
     
  12. cf355

    cf355 F1 Rookie

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    #12 cf355, Dec 20, 2015
    and some people buy an (expensive) specialized socket tool for this adjustment (setting the gap ) but it is not needed....just use your needle nose pliers.
    It does not take much effort so the special tool is not needed.
     
  13. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #13 Rifledriver, Dec 20, 2015
    Last edited: Dec 20, 2015
    There is more to it. The manual was written before the cars were even built. It was out of date a very long time ago, and it was a poor, incomplete description to start with.
     
  14. SoCal1

    SoCal1 F1 Veteran
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    #14 SoCal1, Dec 20, 2015
    Do you set the new cold belt by frequency?

    That was the only thing that worked for us on belt drives on other vehicles.
    Reading the. If I remember correct 360 WS manual I see that had touched base on that also

    :)
     
  15. carwhisperer

    carwhisperer Formula Junior

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    #15 carwhisperer, Dec 20, 2015
    Can someone please answer my question? :)

    How do you position the arm?
     
  16. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #16 Rifledriver, Dec 20, 2015
    Yes but due to the use of that tensioner you can get a correct reading with a very incorrectly adjusted belt due to a minor misunderstanding of the correct procedure which has never been very well verbalized in print. The tensioner was a great cure for a non existent problem. The set and forget manual tensioners used on every single belt drive Ferrari motor except the 355/360 was zero trouble, never failed, never had an update, a TSB or a recall and the belt life or operation never suffered for it. Some junior engineer decided he needed to fix that which ain't broken and we are still suffering for it.
     
  17. lotusk

    lotusk Formula 3

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    #17 lotusk, Dec 20, 2015

    You crack me up
    Keep em coming
     
  18. SoCal1

    SoCal1 F1 Veteran
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    #18 SoCal1, Dec 20, 2015
    Thank you

    I was curious about this and you confirmed. Setting a gap upstream with a tensioner is doing the same thing to achieve set tension in a less trouble free manor

    I'll keep my tension gauge those 3-4 inch harley belt drives

    :)
     

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