Knocking sound from RH rear of car | FerrariChat
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Knocking sound from RH rear of car

Discussion in '348/355' started by moretti, Jan 7, 2014.

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  1. moretti

    moretti Five Time F1 World Champ
    Lifetime Rossa Owner

    Nov 1, 2003
    59,756
    Australia
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    John
    #1 moretti, Jan 7, 2014
    OK, I have a RHD 355Ch and in the last couple of weeks it has developed a knocking sound like a wheel weight is hitting the caliper only on deceleration, under light throttle or more the noise disappears and if I push the clutch pedal to the floor the noise remains but not as loud.

    I need to take the car 150 kms for it's major service later this month but am unsure if I have a major issue and should get it trailered.

    I have put the car on my 2 post hoist and ran the car in gear with no noises, but when I turned the rear wheels by hand I get a faint knock from the RH wheel but the LH wheel is smooth and noise free.

    I'm suspecting CV trouble but have been told it's possibly the gearbox bearing and I should stop driving the car immediately.

    Anyone else had this issue ?

    TIA John
     
  2. ernie

    ernie Two Time F1 World Champ
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    Nov 19, 2001
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    The Bad Guy
    #2 ernie, Jan 7, 2014
    Last edited: Jan 7, 2014
    My guess is either a bad cv joint, but those usually click, or a bad wheel bearing.

    A few years ago I had the knocking in my 348 and it was a bad wheel bearing + a worn axle hub flange because of the bad bearing. The knock came from the flange bolts hitting the the bolts on the cv joint. However the 355 cv joint bolts to the hub through the flange, it doesn't get bolted to it like the early 348s.

    Is it more prevalent when you are turning? If it does it more when you are turning one way vs the other it could be because that side is getting loaded more.
     
  3. moretti

    moretti Five Time F1 World Champ
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    #3 moretti, Jan 7, 2014
    Thanks Ernie, yes, it does sound louder turning one particular way.

    A weird thing was it disappeared for an hour after I put the car up on the hoist and removed the two diffuser panels and then put new bolts in them when I re-assembled them but then returned and is progressively getting louder hence my Cv feeling
     
  4. RWP137

    RWP137 Formula 3

    Apr 29, 2013
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    #4 RWP137, Jan 7, 2014
    This similar noise occurred on my car, but at the right front wheel. The metal clip holding the brake pads wasn't installed correctly, so the inner pad was moving slightly creating a knocking sound. It was a super easy fix and worth a shot to look at...
     
  5. vvassallo

    vvassallo F1 Veteran

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    Vince V
    #5 vvassallo, Jan 7, 2014
    Just jack it up and get under there to isolate the problem. Moving some parts around will tell you if it is any one of those items identified earlier - brakes, CV or bearing. The diagnostic should not be too involved or complicated. Let us know what you find.
     
  6. moretti

    moretti Five Time F1 World Champ
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    Nov 1, 2003
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    #6 moretti, Jan 8, 2014
    I put it on my hoist and spun the wheels a few weeks back, at that time it sounded like wheel bearing as it made a light clicking noise as I turned the wheel and I imagine under load it would be a louder click.

    I'm going to put it up again and have another look, last time I put it on the hoist it disappeared for an hour when I took it for a drive kaing me think I had found the diffuser to be loose.

    Thanks for the ideas guys, sometimes you can't see the forest for the trees
     

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