[Lifetime Warranty] 537338701 Trimmer Head Bump Knob - Pack of 2

537338701 Trimmer Head Bump Knob

Key Features

• Direct replacement bump knob for string trimmer heads.
• Activates the line-feeding mechanism when tapped on the ground.
• Constructed from durable, high-impact plastic for extended wear life.
• Enables quick and simple replacement of a worn or broken part.

Replaces / Cross-Reference Part Numbers

• OEM Part Number: 537338701

Compatibility & Fitment

• Trimmer Head Models:Fits Husqvarna T-25 and T25 heads.
• Compatible Brands:Husqvarna, Jonsered, RedMax.
• Select Husqvarna Trimmer Models:122C, 124C, 124L, 125L, 125LDx 128L, 128LD, 128LDx, 128R, 128RJ 223L, 223R

When to Replace

• Existing knob is cracked, broken, or worn through from ground contact.
• Trimmer line fails to advance when the head is tapped.
• The knob is loose or will not stay attached to the trimmer head spool.

Installation Tips

• Disconnect the spark plug wire before performing any maintenance.
• Disassemble the trimmer head to access and remove the spool.
• Unscrew the old bump knob from the spool assembly. Note: Threads may be left-handed (reverse).
• Clean any dirt or debris from the spool threads.
• Firmly screw the new knob into place. Do not overtighten.
• Reassemble the spool and trimmer head housing.

Compatibility & Fitment