failure mode

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.

诊断概览

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

可能根本原因

  • 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

快速检查

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

维修预览

1.

这是完整维修手册中所含故障排除指南的预览。

相关症状

  • 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

包含在完整手册中

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

公开页面仅显示预览。购买完整手册以下载全部维修步骤、图示和验证流程。

FixBeforeBuy

Trusted repair guides, error codes, symptoms, and manuals before you replace your equipment.

Navigation

For technicians

Need the full step-by-step manual? Purchase securely on FixBeforeBuy and download your PDF after Stripe payment.

© 2026 FixBeforeBuy. Repair smarter before you buy.