Summary of Clutch faults
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  1. #1
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    Arrow Summary of Clutch faults

    There are four main clutch faults; theses are:
    1..Slip
    2..Drag or Spin
    3..Judder
    4..Fierceness

    SLIP:-

    Symptons:
    1) Engine accelerates without giving a corresponding increase in vehicle speed.
    2) Smell of burning asbestos ( or Kevlar )
    3) In very bad cases, vehicle will not drive up steep hills.

    POSSIBLE CAUSES:

    Any defect that leads to insufficient:
    A) pressure on clutch plate
    B) friction

    such decects include:
    1 No free pedal movement.
    2 Partial seizure of linkage ( including slave cylinder ) or fouling of the pedalso as to prevent the full return of the linkage.
    3 Worn clutch facings
    4 Oil-contaminated facings. (N.B. Source of oil leakage must be identified. )
    5 defective pressure plate: broken springs(s),partially seized mechanism.


    SPIN or DRAG:-

    ( In the past SPIN was a design fault associated with the weight of the driven plate and DRAG was due to a deceft that could develop during the clutch life. Since the symptoms are similar, both faults are often grouped together.

    Symptoms:
    1) Difficulty in engaging first gear from neutral without making a noise
    2) Jolt when changing gear with the vehicle in motion.
    3) In very bad cases, vehicle will continue to move even when the pedal is fully depressed.

    POSSIBLE CAUSES:

    Any defect that prevents the clean seperation of the driven plate from both driving surfaces. Such defects include:

    1 Excessive free pedal movement caused by the need for adjustment or lack of fluid in the hydraulic system.
    2 Fouling or wear of the linkage such that the pedal cannot be fully depressed
    3 Oil-contaminated facings causing one face to stick to a driving face.
    4 Defective driven plate, buckled plate or seizure on splines. (Sometimes a modification is recommended which involves the drilling of a hole in each rivet to avoid a "Vacuum pocket".)
    5 Misalignment of friction faces.
    6 Partially seized spigot bearing.


    JUDDER:-
    Symptom:
    A severelow frequency vibration which normally occurs when the clutch is released and the vehicle is moved from the stationary position.

    POSSIBLE CAUSES:

    Any defect that prevents the smooth engagement of the clutch. Such defects include:

    1 Jerky pedal operation: sticking cable or slip/grip movement of the pivot.
    2 Engine movement during the take-up of the drive. Often this is caused by a defective tie rod: this is fitted to resist engine or transmission movement. Wear in the drive line or suspension points can also cause this fault.
    3 Oil-contaminated facings such that the slip/grip take-up action is amplified.
    4 Defective pressure plate. Often this is due to the high friction in reigions where the plate should move smoothly through the cover.
    5 Misalignment of the friction faces.
    6 Defective driven plate: broken springs in the hub or a partially sheared plate.

    FIERCENESS:-
    Symptom:
    A sudden move-off of the vehicle even though the pedal is gradually released.

    POSSIBLE CAUSES:

    Any defect that allows the clutch take-up to be faster than the movement of the pedal. Such defects include:

    1 Partial seizure of the pedal linkage or contamination of fluid in the hydraulic operating system. These defects produce an erratic movement of the pressure plate.
    2 Oil-contaminated driven plate.
    3 Misalignment of friction faces.
    Last edited by Mart; 25-01-2002 at 22:08.
    Time waits for no Man and very few Women

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  3. #2
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    Mart, will try see if this can be added to the Tech Archives for everyone to see

    Nice one
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  4. #3
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    Thread Starter

    Thumbs up Cheers.....

    Richie .

    Mike has now added it to the archives .

    Hope it help some-one
    Time waits for no Man and very few Women

  5. #4
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    The biting point on my clutch has slowly moved in last 6 months to end of pedal. i.e. the clutch has to be almost fully released before gear catches.

    No problems with driveability at the moment , but is it a 'danger' signal?

    How can I move biting point back up?

  6. #5
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    Adjust the clutch cable by removing from gearbox end and turning white screw clockwise (bout 5 min job)
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  7. #6
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    no ritchie to lower the biting point you need to screw the plastic nut anti-clockwise.
    some cars will still have the clip attached to the threaded portion which prevents adjustment till its removed.
    it is much easier to adjust if a mate holds the brake pedal up ie foot under pedal and lifted as this lenghthens the cable while adjusting.

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