Curious, 355 Alternator Tensioner Pulley Failures, Frequent? | FerrariChat
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Curious, 355 Alternator Tensioner Pulley Failures, Frequent?

Discussion in '348/355' started by Markphd, Nov 4, 2013.

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  1. Markphd

    Markphd Formula Junior

    Mar 10, 2012
    713
    #1 Markphd, Nov 4, 2013
    Just got to wonder why they are failing on low mileage cars. Even GM/Ford manages to do better than this. Is there a flaw (and hence the change after 28600)?

    Mine **** the bit, and looks like what everyone else who has experienced this failure... Just a destroyed bearing, which strikes me a bit odd.

    Mark
     
  2. lotusk

    lotusk Formula 3

    Nov 3, 2003
    1,840
    London UK
    #2 lotusk, Nov 4, 2013
    There is a Hill Engineering uprated bearing for here...

    Right??
     
  3. bcwawright

    bcwawright F1 Veteran

    Jul 8, 2006
    5,234
    Georgia
    Full Name:
    Bruce
    #3 bcwawright, Nov 4, 2013
    Yes and also the adjuster screw...

    If needed I have.
     
  4. gothspeed

    gothspeed F1 World Champ

    May 26, 2006
    10,244
    U.S.A.
    Full Name:
    goth
    #4 gothspeed, Nov 4, 2013
    If they are not adjusted and tightened correctly, they will not be aligned with the linear rotation of the belt, which means it may see a lateral load and that will increase the wear on the bearing.

    There are two adjustments, one sets the tension (bolt running vertically) and the other locks that position in place (nut and shaft that goes thru the bearing itself). I have seen some 355s, where only the tension bolt was set and the other was not tight. :eek:
     
  5. Markphd

    Markphd Formula Junior

    Mar 10, 2012
    713
    #5 Markphd, Nov 5, 2013
    That would likely explain it. I have a unknown service history F355. Mind you, when I actually get in there and repair it, it will be done correctly. Since I am beginning the car's first real maintenance period under my stewardship, the engine is coming out along with anything else that looks like it needs some attention.

    It's a beautiful car... I do know that some stuff I will farm out, but that's primarily any machine work, the rest I will tackle on my own.
     
  6. roadracer311

    roadracer311 Formula 3

    May 6, 2009
    2,398
    San Francisco
    Full Name:
    Paul
    #6 roadracer311, Nov 8, 2013
    The other thing that probably causes the tensioners to fail is that turning the tensioning bolt to the right makes the belt more loose. So it's lefty-tighty righty loosey for the tensioner bolt! Easy to end up with a belt that's way too tight or way too loose!
     
  7. Markphd

    Markphd Formula Junior

    Mar 10, 2012
    713
    #7 Markphd, Nov 15, 2013
    What an absolute pain in the ass. I was able to finally back out the studs. Naturally, I had to press the bearing outer race out of the pulley and the inner race off the screw. Thankfully I own the right tools to do the job correctly. This would have been so much easier if the engineers at Ferrari had even given a moment's thought to this common maintenance item.

    One quick bit of advice for those doing this, you don't need to use mole pliers or vice grips to get the studs out. There is enough room to remove the studs by doubling up the nuts on the studs and extracting them that way without damaging the studs should you wish to reuse them. (Personally, while I appreciate the fact that studs are superior for the job, I am going to revert to using a bolt on top at a minimum and perhaps slightly shorter studs on bottom.

    It didn't need to be this tough, and it should have never failed in the manner that it did. I am fortunate that I didn't lose the $653 pulley as a result of this failure or and fortunate that more damage did not occur.

    Mark
     
  8. UConn Husky

    UConn Husky F1 Rookie

    Nov 11, 2006
    4,425
    CT
    Full Name:
    Jay
    #8 UConn Husky, Nov 18, 2013
    I replaced my alternator pulley a few yrs ago when it was squeaking, and guess what, squealing again. Once it warms up it goes away :D Almost time for the engine out so it'll wait until then...
     
  9. junglistluder

    junglistluder F1 Rookie
    Owner Silver Subscribed

    Mar 23, 2007
    3,631
    VA
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    Brendan
    #9 junglistluder, Nov 18, 2013
    Alternator tensioner bearing should be part of every major service. It's only a $50 part and the belt comes off anyway. Mine failed while on the highway, fun time!
     
  10. Markphd

    Markphd Formula Junior

    Mar 10, 2012
    713
    #10 Markphd, Nov 18, 2013
    I had just gotten my Ferrari off the boat when it arrived in Guam. I have spent the better part of the last year recovering from surgeries and defending a dissertation, so unfortunately it sat for a long, long time. Finally, now, I am able to work on it.

    I have a lot of disdain for how impossible some of these bolts are to get to, I have never had a car give me such trouble getting it apart. It was even screwing with me when I put the belt tensioner back in... however, that's nothing compared to wresting the stock headers out. I swear... I want to hurt the engineer who didn't leave clearance to get on those bolts easily!!!
     

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