308 Centerforce clutch | FerrariChat

308 Centerforce clutch

Discussion in 'Technical Q&A' started by mattboyd, Dec 15, 2003.

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  1. mattboyd

    mattboyd Karting

    Dec 14, 2003
    Fredericksburg, VA
    Full Name:
    Matt Boyd

    When I purchased my car, the previous owner had recently installed a Centerforce carbon kevlar clutch. I can't find out "out of the box" that is listed as a 308 application. Can anyone help with a part source/part number?

    '85 Euro 308 GTS/QV
  2. Dave

    Dave F1 Rookie

    Apr 15, 2001
    Little Rock
    Full Name:
    David Jones
  3. Tig368

    Tig368 Rookie

    Nov 23, 2003

    I called centerforce several years ago. While things may have changed since then, they basically told me that they could rebuild a 308 pressure plate and clutch disc. At the time, they didn't have any plans to stock a 308 clutch, but they had a department that could do special case work such as the clutch rebuild. I forgot how much it cost, but I think it was reasonable.

    Alan Ing
  4. mattboyd

    mattboyd Karting

    Dec 14, 2003
    Fredericksburg, VA
    Full Name:
    Matt Boyd
    I called them today and they said the same. Only problem is the ~4 week turnaround! I don't want to be without for that long! :-( But the estimate was <$250, so cheaper than OEM (and better).

  5. mk e

    mk e F1 World Champ

    Oct 31, 2003
    The twilight zone
    Full Name:
    The Butcher
    I was just doing some clutch hunting for my car and found something odd. Nick sells a twin disc clutch which the clutch part is made by quarter master. Once you install it, the replacement plates are a $200 an off-the-shelf part. But when you look at their catalog, there are no ferrari parts. So I'm thinking some other car has the same trans splines, porsche maybe??
  6. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    Groton, MA
    Full Name:
    Verell Boaen
    I'm helping a 328 owner with some concerns about a newly installed clutch. The concerns are:

    1) Clutch Pedal pressure gets very very light at high (6k-7K) RPM.

    2) At the same high RPM it becomes hard to shift gears.

    I was puzzled by this one, but this AM while driving my 308 to work, I remembered the Centerforce clutch. The Centerforce claims that it's diaphram weights overcome lightened PP pressure at high RPMs.

    My clutch is a stock B&B only a couple of years & maybe 3500 miles old, so I'm confident that it's working normally.

    I was on an empty stretch of back road, so I down shifted into 1st & brought the engine up to ~6,000 RPM. When I up-shifted into 2nd sure 'nuff, clutch pedal pressure had all but disappeared!!! To make sure I wasn't dreaming, I repeated it a few more times.

    Just don't remember ever hearing about 3x8s exhibiting this effect.


    2) Significant shifting resistance appears at high RPM.

    Until this AM I'd been assuming that both symptoms were related and it's been driving me nuts.

    Given that the pedal pressure decrease with RPM is normal, I believe that the most likely causes of shifting difficulty at high RPM is either the clutch not fully releasing, or else his synchros aren't up to the job.


    Suspect it's one of the smaller Chevvys, Ferrari uses a 12 spline disc & I'm pretty sure that a Chevvy clutch alignment tool can be used for Ferraris if you put a sleeve or tape on the pilot shaft to build it up.
  7. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    Austin TX
    Full Name:
    Brian Crall

    He called me too. It sounds like a classic case of either an incompatibility of the parts being used or an assembly problem causing the diaphram to go over center and centrifugal force trying to hold the clutch in that position. Many diaphram clutches also in that situation start reapplying pressure to the disc preventing a shift. The car needs to be taken apart and eyeballed by someone that knows what they are looking at.

    Many TR clutches in the early days were incorrectly shimmed by AP and did the same thing. It got so we could tell just by eyeballing the angle of the spring fingers after it was bolted up. In severe cases the clutch pedal would not return on a high RPM shift.

    The 308 spline size and in fact the entire clutch assy was common to a British sports car of some variety. A TR6 or something of that ilk.
  8. robertgarven

    robertgarven F1 Veteran

    Feb 24, 2002
    Ventura, California
    Full Name:
    Robert Garven
    I have felt this too with the standard B&B clutch, not sure what causes it?

  9. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    Groton, MA
    Full Name:
    Verell Boaen
    So the lightened pedal pressure is normal.

    Seems to make a case for a Centerforce clutch...

    I tend to agree with Bryan, the diaphram is being depressed past center causing the pp to grab the disc.

    Suspicion is the clutch linkage /cable are miss-adjusted. Gave the guy a copy of the clutch adj procedure & recommended he go over it with his service tech to make sure that's what was done.

    If it isn't an ass'y/adj problem, then the PP has to be bad.
  10. Van de Merghel

    Aug 18, 2006
    Anaheim, CA
    I just got through reading your thread because I have the same problem with the replacement clutch on 85 QV. At high RPMs I feel I could engage the clutch effortlessly with my little finger. As a result, I don't push it above 5000 RPM fearing it might jam engaged and self distruct behind my back! I purchased the complete clutch assembly from a well known/reputable Ferrari parts house in 1994. The clutch is made in England by Automotive Products (AP) (CAV 8) HE 4562Q, Cover Assy 42K ( I still have the box it came in). I took the clutch out twice to see if I had done something wrong but that's the way it is. I did talk to the folks I bought the clutch from and they were of no help. Essentially, we never had any reported problems with this clutch, you bought it, its your problem. I've been living with it since 94. The timing belts are on my agenda now.


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