When checking the free travel of the torsional damper, the secondary part of the DMF is rotated using the lever counterclockwise until encountering slight counterpressure or feeling the spring force of the torsional damper. The free travel should not be more than six teeth of the starter ring gear. If it is more than six teeth, it is highly likely that internal damage exists and the DMF will need replacing.
When checking the axial bearing site, the secondary part of the DMF is moved evenly to and fro using the lever within the clearance. If the secondary part rubs on the primary side and/or scraping noises can be heard, the DMF will need replacing.
Note: The tilt of the secondary part does not provide any indication of the condition of the DMF; this may be larger or smaller due to the design.
To check the spring force of the torsional damper, the secondary part of the DMF is increasingly rotated right and left against the spring force of the torsional damper in both directions using the lever. The spring force should be noticeable during the check in both directions and with an evenly increasing force. Grinding or scraping noises are indicative of a defect – the DMF will need replacing.
The radial bearing site is checked by pressing the secondary part of the DMF lightly and evenly using the lever, while trying to move it radially by applying light force. During testing, no or only a slight radial clearance should be discernible. In the event of large radial displacement, the DMF must be replaced.