FM-21: FM-21 INTERNAL GRINDING, KNOCKING, OR SCRAPING AT NO LOAD

Continuous abnormal grinding, knocking, or scraping noises occur at no load with the bit removed.

• Debris or damage is present at the chuck nose
• Front support, bearing, or anvil is worn
• Reduction gears or hammer parts are damaged
• A loose internal part is contacting the rotating drive

1. No-load operation is smooth except for normal motor sound and an occasional direction-change click.

1.

This is a preview of the troubleshooting guidance included in the full repair manual.

• With the bit removed, the driver makes continuous abnormal grinding, knocking, or scraping.

  With the bit removed, the driver makes continuous 1. Remove the pack and bit; inspect the chuck nose, housing, and vents for

• root cause analysis
• tools needed
• step-by-step repair procedure
• diagrams
• exploded views
• post-repair checks

Public pages show a preview only. Purchase the full manual to download complete repair steps, diagrams, and verification procedures.