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308 QV alternator belt melted??

Discussion in 'Technical Q&A' started by mk e, Nov 1, 2003.

  1. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,428
    The twilight zone
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    The Butcher
    This is the second time in 2 years I;ve had this happen. When I start it sometimes i hear the belt squeel faintly. If I let it idle, it stops and I don't hear it again. If I touch the throttle I get this. Anyone else?
     
  2. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,428
    The twilight zone
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    The Butcher
    hmmm, no pic??? I'll try again.
     
  3. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,428
    The twilight zone
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    Anyway, it melted all over the pulleys, I wish you could see it
     
  4. Meister

    Meister F1 Rookie
    Silver Subscribed

    Apr 27, 2001
    4,896
    Duluth, MN
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    The Meister
    Check the alignment of your pulleys. I put on a new belt earlier this year and got the squeal... eventually burned it off... not fun. If the pulleys are out of alignment they will generate enough heat to melt the belt. Mine was cured with one washer between the upper alt braket and the timming belt cover. Good luck.
     
  5. sparta49

    sparta49 F1 Veteran
    Rossa Subscribed Owner

    Mar 3, 2001
    7,794
    LA
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    Frank
    I had the same thing happen on my QV after replacing the water pump, alt. and alt mounting bushings it turned out the pulley was out of alignment. a washer between the block and the alt . bracket solved the problem
     
  6. Cooly0

    Cooly0 Karting

    Nov 2, 2003
    129
    Milford
    Full Name:
    Jozy
    I had the same problem a few weeks ago. I knew from the start that the sqeal was bad. To Get rid of it, make sure the nuts are tightened to the extreme to remove the possibility of movment. Start by Getting the alternator as far down the line as possible making the belt tight. When you push on the belt with 4 lbs of force it should only move 2-3 CM
     
  7. Cooly0

    Cooly0 Karting

    Nov 2, 2003
    129
    Milford
    Full Name:
    Jozy
    I had the same problem a few weeks ago. I knew from the start that the sqeal was bad. To Get rid of it, make sure the nuts are tightened to the extreme to remove the possibility of movment. Start by Getting the alternator as far down the line as possible making the belt tight. When you push on the belt with 4 lbs of force it should only move 2-3 CM.
     
  8. Verell

    Verell F1 Veteran
    Owner Consultant

    May 5, 2001
    6,967
    Groton, MA
    Full Name:
    Verell Boaen
    Mk e,

    1) UNDER-TENSIONED BELT MELTS ITSELF
    The Gates PolyFlex belts require substantially more tension than conventional automotive belts. If the belt is squealing just after startup, or when the throttle is tapped, it should be tightened a bit more. The 1st time I replaced my belt I was amazed at how much tighter it had to be than a conventional belt.

    The alternator produces max belt load just after startup while it's topping off the battery. Also the belt & pulleys are cold which seems to make it slip & squeal.

    Tapping the throttle accelerates the engine, & the belt must accelerate the wp & alternator. The increased load on the belt due to accelerating them can cause it to slip & squeal.


    2) WATER PUMP BEARING FAILURE MELTS BELT:

    I had my wp/alternator belt melt a few years back, about a month after I got my 308 QV. Couldn't figure out the cause. Replaced the belt & drove it all that summer.

    Next spring I discovered that the WP's bearings were shot.
    When I rebuilt the pump, I found that the inner bearing's balls had completely disentigrated! Also the brass impeller had been rubbing against the inside of the wp housing.

    Apparently the inner bearing had seized just long enough to destroy the belt. Once things cooled down the bearing had unsiezed. Since then I've learned that this is pretty common.

    With the belt off, carefully check your waterpump for any of the following:

    - Something dripping out of one of the weep holes on the bottom of the wp's nose. ie: brown stain or gunk, coolant or coolant stain. Also make sure the weep holes aren't clogged(mine were, hence no telltale stain).

    - WP shaft should have essentially no axial or radial play. Any play is a sign of a failed bearing.
     
  9. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,428
    The twilight zone
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    The Butcher
    Well, the belt was out of alignment. And a washer up top did help it alot, although I don't understand why. The parts book doesn't show anything there and it just seems wrong that there is play in the main mount. I'll have to take a bettter look at it, but it's working now. I also now remember that the belt that just melted was an old belt. I put a new one on 2 years ago, then melted it off by not tensioning it enough. Wanting to drive, I though the old one back on and promptly forgot to get a new one. So maybe it was just flat worn out now, I guess it it was wron enough to drop down to the bottom of the pulley, no amount of tension would stop it from slipping.

    I don't know how you guys tension the belt, but I bought a couple 1/2 inch bolt and a coulpler at the harware store. Then I wedge it between the crank and alternator pulleys. It lets me hold the belt good and tight while tighting the bolts.
     
  10. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,428
    The twilight zone
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    The Butcher
    Oh, the service manual calls for 5mm movement with a 3kg load. Way tighter than 2-3cm at 4 lbs (1.8 kg).
     
  11. sparta49

    sparta49 F1 Veteran
    Rossa Subscribed Owner

    Mar 3, 2001
    7,794
    LA
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    Frank
    All the parts were there on mine also, who knows I have a theory that everyone of them left the factory out of alignment and overtightening the belt cures the squeal and failure for a while but destroys the water pump hence all the rebuilt waterpumps. just my crazy theory :)
     

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