ARP 129-2503 Harmonic Balancer Bolt Kit | 2001-2019 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax V8

Features: 

• M18 x 1.5 Thread Size
• 12-Point Head Style
• 190,000 psi
• 8740 Chromoly Fastener Material
• Ensures Balancer is Locked in Position
• Bolt Only
• Increased Strength and Reliability

Absorbs Heavy Vibrations With Higher Speeds

The ARP Harmonic Balancer Bolt Kit enhances your vehicle's usage of horsepower while absorbing the excessive vibrations from increasing your vehicle's RPM by keeping the harmonic balancer locked into place. The bolt kit has increased strength and reliability compared to the OEM model to keep your engine and components safe and secured with the harmonic balancer in place. Enjoy cruising down highways or attending some race events and enjoy the enhanced ride quality.

Capable to Handle High RPM and BHP Levels

With the ARP Harmonic Balancer Bolt Kit keeping your harmonic balancer in place, you get benefits boosted to keep your engine running it's best. With your harmonic balancer bolted in place you will notice a reduction in heavy vibrations or rattling, makes your RPM and BHP easier to handle, and keeps your vehicle safe during higher speeds. Having the bolt kit installed your engine can have an increased lifespan as the harmonic balancer ensures other vehicle.

Vehicle Fitment: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 GM Duramax 6.6L V8

Notes:

• Fits 2001-2019 GM 6.6L Duramax V8 engines
• Designed to secure the harmonic balancer under high stress
• M18 x 1.5 thread pitch with 12-point head design
• Manufactured from 8740 chromoly steel for superior strength
• Rated at 190,000 psi tensile strength
• Ideal for high RPM and high horsepower applications
• Helps reduce vibration and improve engine balance
• Prevents balancer movement that can lead to crankshaft damage
• Not compatible with non-Duramax GM V8 engines (e.g. LS-series)
• Includes bolt only—no washer or additional hardware
• Designed for performance, racing, and heavy-duty usage
• Improves long-term reliability of rotating engine components