Fits: 2001 thru 2025 Chevy Silverado/GMC Sierra 2500HD/3500HD LB7/LLY/LBZ/LMM/LML/L5P Duramax Diesel

Designed for all models of the Duramax 6.6L, this reamer tool effectively removes carbon and soot buildup from glow plug holes. Proper cleaning is essential to prevent glow plug tip breakage during installation, which can lead to severe engine damage—including harm to the piston, valves, and cylinder head—if debris falls into the combustion chamber. When replacing ceramic glow plugs, using this tool is not just recommended—it’s mandatory to ensure a safe and reliable installation.  

Merchant Automotive recommends using a small amount of grease on the flutes to collect any carbon that is removed from the bore.  Simply turn this tool by hand.  No need to use a wrench or socket.

Features:

• Matches EN-52074’s action for all 6.6 L Duramax engines (2001–present)
• Precision pilot & reamer keeps alignment straight to prevent damage
• Hand-turn operation—simply rotate by hand (no wrench or socket required)

Replaces:

• GM-52074
• Kent-Moore EN-52074
• OTC-7223

Note:

• GM Service Bulletin