Check for Damaged Components
All following checking procedures have to be carried out at installed dual mass flywheel. For visual check at vehicle very bright light and a additional bright and small pocket lamp is necessary. Damages like grease on primary flywheel and loose ore missing balance weights cannot be checked at installed condition. During visual check material alteration can be stated which eliminate a further operating suitability.
For comparison different damages at dual mass flywheel with the corresponding further procedure are presented here.
- NOTE:
In case of mechanical damages at plain bearing the dual mass flywheel has to be replaced.
Inspect plain bearing (1) for damages.
Dependent of the manufacturer damages can be detected through ventilation openings of secondary flywheel. Parts of the bearing (1) are detached or lie loose around the bearing bolt.
- NOTE:
Light abrasion on frontal areas of teeth is allowed. If problems occur during starting the engine the dual mass flywheel has to be replaced.
Inspect toothed ring (1) for damages.
The toothed ring is needed to start the engine. Through a lot of starting procedures and/or an incorrect engaging starter signs of abrasion can occur on teeth of the toothed ring. The profile of damages can reach from only low signs of abrasion up to heavy material removal. The installation of a pulse-generator ring depends on the manufacturer.
The image shows signs of abrasion and mechanical damages at toothed ring (1), they occur through abrasion due to a lot of starting procedures. In this case the dual mass flywheel has to be replaced.
- NOTE:
The check must be carried out only by hand without any tools.
Inspect tilt clearance.
At dual mass flywheel the additional-mass ring looms over the gap between primary and secondary flywheel.
- NOTE:
An absolute clear measurement is not possible with this check due to the different applied forces of the several workshop employees during the check and the different clearance of tilt play between the different suppliers.
Embrace dual mass flywheel and apply thumbs onto the outer radius of secondary flywheel.
- Apply pressure onto the secondary flywheel alternating on upper, lower, left and right side
During the tilt clearance check a functional metal rattling noise may occur.
A tilt play (1) is normal and does not require a replacement of the DMF, Check whether the free angle and the spring pressure are available on both sides. If the rotation of the flywheel at one or both sides impossible the flywheel is defective and has to be replaced.
- NOTE:
Before the inspection of the clearance angle, the dual mass flywheel should be rotated several times in a clockwise and counter clockwise direction. There may be light scrubbing, clicking or metallic noises as the flywheel is rotated in each direction.
Inspect clearance angle (1).
- The clearance inspection is to check if the secondary flywheel exhibits a normal amount of movement in relation to the primary flywheel, in both directions, as the internal flange contacts the ARC springs.
- If the flywheel cannot be moved in either direction or exhibits a binding condition, the flywheel is defective and must be replaced.
Rotate secondary flywheel counter clockwise until the counter force (spring force) is clearly noticeable
- Release secondary flywheel slowly until there is no spring force on the flywheel.
Mark position with a vertical line on secondary flywheel (1) and on toothed ring (2).
Rotate secondary flywheel clockwise until the counterforce (spring force) is clearly noticeable.
- Release secondary flywheel slowly until there is no spring force on the flywheel.
Apply a new marking on secondary flywheel (1) on the height of the marking on the toothed ring for starter (3).
- Count the number of teeth from marked tooth up to the height of the first marking on secondary flywheel (2).
- For the functional movement of the secondary flywheel, up to 6 teeth are allowed.
- If the movement exceeds 7 teeth, the flywheel must be replaced.