In case of defective or worn DMFs we recommend the SACHS testing tool to check the dual-mass flywheel: The DMF testing tool for passenger cars and light commercial vehicles enables easy and reliable dual-mass flywheel diagnosis and inspections of DMFs in installed or disassembled condition.
Diagnosis Made Easy:
Testing Tool for Dual-Mass Flywheels
For SACHS spare parts various catalogs are available as PDF for download free of charge, e.g. the SACHS shock absorber or the SACHS clutch catalog.