328GTS - Tensioner alignment off | FerrariChat

328GTS - Tensioner alignment off

Discussion in 'Technical Q&A' started by tfrancis, Jan 3, 2004.

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  1. tfrancis

    tfrancis Karting

    Nov 3, 2003
    Memphis, TN
    #1 tfrancis, Jan 3, 2004
    Last edited by a moderator: Sep 7, 2017
    I've put new belts on my 86' 328GTS but notice that the waterpump belt was out of alignment. This has become a very time consuming and frustrating problem. Can someone tell me if I've got the correct washers on my tensioner?
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  2. tfrancis

    tfrancis Karting

    Nov 3, 2003
    Memphis, TN
    #2 tfrancis, Jan 3, 2004
    Last edited by a moderator: Sep 7, 2017
  3. Meister

    Meister F1 Veteran
    Silver Subscribed

    Apr 27, 2001
    Duluth, MN
    Full Name:
    The Meister
    From the pic it looks like it's too far out to me. I'd try it without the washers and try to put some kind of straight edge from one pulley to the other to see if the alignment gets better... a ruler, metal bar stock or something like that. My 2V doesn't have a tensioner so I don't have any first hand experience... just my thoughts. Good luck
  4. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    Groton, MA
    Full Name:
    Verell Boaen
    Sure looks out to me. Try this trick:
    Go to the local HW store & get a piece of 1/4" square 'key stock' that's about 2" longer than the centerline between the WP & tensioner pulleys.

    Remove the wp belt. Insert the the edge of one end of the stock into the v-groove on wp's pulley & clamp it into place with a C-clamp. The pulley should align the piece of stock along the center of the groove.
    Rotate the stock over to where it touches the tensioner pulley. The stock should exactly drop into the tensioner pulley's groove.

    Alternatively, clamp the stock so that it makes a chord across 1 edge of the wp pulley & use the same technique to check the tensioner position.
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    I don't think there is any "correct" for the washers that you show between the idler pulley base and the cam belt cover (I couldn't find any "shims" called for in that location in the 328 SPC, but I didn't look super hard -- that's your homework ;)). If adding a shim or 2 in those locations would improve an obvious "bad" alignment of the idler pulley (without shims) relative to the WP and crankshaft pulleys, I think they'd be fine to include, but it sure doesn't look like what you've got there is helping improve the pulley alignments -- just my 2 cents...
  6. atheyg

    atheyg Guest

    I noticed on most of my pulleys,wp,alt,a/c they are all offset, I believe this is on purpose to put less strain on the bearings/pulleys at high rpms
  7. Mark 328

    Mark 328 Formula Junior

    Nov 6, 2003
    Orange, Ca
    Full Name:
    Mark Foley
    I am doing the belts on my '87 328 right now. My water pump tensioner does not have any spacers or washers under it and it fits pretty straight, however it is not perfect and the tensioner pulley is showing a little more wear on one side.
    My A/C compressor seems to be out of alignment by an eighth inch or so.
    When I put the A/C compressor back-in I am going to try to shim it out for better alignment.
    Somebody mentioned that this misalignment would reduce stain at higher RPMs? I do not understand this concept and would appreciate hearing from others on this concept.

  8. tfrancis

    tfrancis Karting

    Nov 3, 2003
    Memphis, TN
    #8 tfrancis, Jan 8, 2004
    Last edited by a moderator: Sep 7, 2017
    Well after extensive measuring using a straight edge (as suggested by Verell....picture below) I've discovered that the water pump is indeed exactly aligned. The tensioner was off almost 1/8". Certainly don't know what mechanic along the way did this job. I've gotten closer using different washers (.075")... only off by .025" now but I'll by the correct size (.050") so it's right.
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  9. thecarreaper

    thecarreaper F1 World Champ
    Silver Subscribed

    Sep 30, 2003
    great thread!

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