When a clutch assembly is being replaced and heat marks are found on the flywheel surface, Technician A says to try to remove the marks with an emery cloth first. Technician B says if the emery cloth fails to remove the marks, the flywheel must be replaced. Who is correct?

When a clutch assembly is being replaced and heat marks are found on the flywheel surface, Technician A says to try to remove the marks with an emery cloth first. Technician B says if the emery cloth fails to remove the marks, the flywheel must be replaced. Who is correct?

• A. Some heat marks can be removed using an emery cloth.
• B. If the emery cloth fails to remove the marks, the flywheel must be replaced.
• C. The flywheel should be polished with sandpaper.
• D. Replace the flywheel immediately without trying any treatment.

Answer: (D)

Heat marks on the flywheel signal thermal damage that can compromise surface flatness and strength. Trying to polish or sand the marks away can remove material and alter the flywheel’s thickness or true running surface, potentially masking cracks or warping. A clutch relies on a true, solid surface for proper engagement; if the flywheel’s integrity is in question, reusing it risks clutch chatter, slipping, or even a catastrophic failure. For that reason, the safest and most reliable course is to replace the flywheel rather than attempting any cleanup.

Heat marks on the flywheel signal thermal damage that can compromise surface flatness and strength. Trying to polish or sand the marks away can remove material and alter the flywheel’s thickness or true running surface, potentially masking cracks or warping. A clutch relies on a true, solid surface for proper engagement; if the flywheel’s integrity is in question, reusing it risks clutch chatter, slipping, or even a catastrophic failure. For that reason, the safest and most reliable course is to replace the flywheel rather than attempting any cleanup.