In-Depth i-CTDi Diesel Clutch/Flywheel Inspection Method

Discussion in 'Technical Articles' started by Ichiban, Monday 23rd Jul, 2012.

  1. Ichiban Founder Staff Team

    England CJ Leeds
    Model Model Code Year Model
    ACCORD 4DCN104, 05, 06, 07, 08
    ACCORD TOURERCN204, 05, 06, 07, 08
    Civic 3DFN307, 08, 09, 10, 11
    Civic 5DFK306, 07, 08, 09, 10, 11
    CR-V I-CTDIRD9, RE605, 06, 07, 08, 09
    FR-VBE506, 07, 08, 09

    Due to the nature of the dual mass flywheel system it can be difficult to correctly asses the parts' serviceability during any related repair. The inspection method in this article is intended to clarify the inspection process.

    Inspection Method.

    A dual-mass flywheel is used to reduce driveline vibration/noise, particularly when driving at low engine

    A faulty dual-mass flywheel CANNOT cause any form of clutch problem. The only issues that can
    arise from a faulty dual mass flywheel is clutch judder or engine vibrations.

    The flywheel consists of two masses: the primary mass (A) is fixed directly to the crankshaft (as per a normal
    flywheel), the secondary mass (B) is connected via large torsional springs (C) which allow for up to 55º of
    rotation in either direction.

    Diesel fly 1 AOCUK.
    When the transmission has been removed it is possible to rotate the secondary mass by hand. Depending on
    the final resting position of the friction damper the rotational movement can feel very different.

    Checking process.

    With the flywheel fixed to the engine check it is possible to rotate the secondary mass by hand. The first part of
    the movement of the torsional springs should be relatively easy, and this is the only movement that should be checked.

    1) Take hold of one of the clutch cover plate locating dowels with just your finger and thumb, now rotate the
    secondary mass as far as possible in a clockwise direction using only light pressure from your fingers. Mark the position that the secondary mass stops in against the primary mass as shown below.

    Diesel fly 2 AOCUK.

    2) Now using your finger and thumb on the dowel again ,and light pressure, rotate the secondary mass in an
    anti-clockwise direction until you feel strong spring pressure, now let go of the secondary mass (it may move backwards slightly, but this is okay). Mark the secondary to primary mass position again, as shown below.

    Diesel fly 3 AOCUK.

    3) You can now measure the distance between the 2 marks that you have made. If you have used a thick pen
    then try to measure in the centre of the pen lines as shown below. In this example the movement is 24mm, which is well within the specification shown below.

    Diesel fly 4 AOCUK.

    You should never use any type of tool e.g. lever bars, screwdrivers or prybars etc to move the secondary mass.

    The 'new part' specification is between 3.5 - 35.0 mm, however for used flywheels the upper limit is increased to 38.5 mm (+ 10%) . If the measurement is within specification the flywheel can be reused.

    If there is no movement of the inner flywheel or the measurement is not within specification then the flywheel must be replaced. Warranty replacement should not be carried out if the flywheel is within specification.

    Flywheel Preparation.

    The friction surface of the Dual Mass Flywheel can be re-dressed with an abrasive cloth provided there are no
    heat cracks or scoring

    Diesel fly 5 AOCUK.

    Diesel fly 6 AOCUK.

    New Clutch Part Check.

    Before fitting new clutch cover check the Self Adjust mechanism is in the correct position. It is possible that if
    the new part is mishandled or subjected to any severe shock that the mechanism can move away from the correct start position which will affect the operation of the clutch.

    Check for alignment of "X" mark on adjustment mechanism.

    Note: X mark is engraved into clutch mechanism material by supplier and will remain visible.

    If the mechanism is found to be in the incorrect position the part should not be used

    Diesel fly  8 AOCUK.

    Diesel fly 7AOCUK.
  2. Paul Expert Advisor ★ ★ ★ ★ ★

    Always wondered how they checked. Great insider info CJ.
  3. Ichiban Founder Staff Team

    England CJ Leeds
    Its easy when you know :Wink:
  4. Paul Expert Advisor ★ ★ ★ ★ ★

    The same with everything buddy :Wink:
    Ichiban likes this.