ARP GM Duramax 6.6L Harmonic Balancer Bolt Kit

This ARP performance fastener, stud, bolt, tool, or assembly is the GM Duramax 6.6L Harmonic Balancer Bolt Kit. Confirm the exact engine or vehicle application, thread size, length, material, strength series, included quantity, installation lubricant, tightening sequence, and current ARP torque specification before ordering.

Key Features

• ARP2000 Alloy Construction: Forged from high-tensile 8740 chromoly steel with over 220,000 psi strength to withstand 1000+ hp builds.
• Complete Kit Contents: Includes one M16 x 140mm main bolt one 12-point head nut and heavy-duty washer for full replacement.
• High Torque Rating: Rated for 300 ft-lbs dry or 340 ft-lbs wet torque far beyond OEM specs for rock-solid hold.
• Precision Machined Threads: Perfect fit into crankshaft nose eliminates cross-threading and ensures even clamping load.
• Direct OEM Replacement: Bolts in without modifications maintains stock balancer alignment and timing.
• Custom heat treatment process delivers consistent performance.

Fitment

Specifications

What’s Included

One new ARP hardware kits – other in the exact configuration and quantity identified by this listing. Brackets, wiring, air lines, fittings, switches, fasteners, fitting kits, fluids, covers, and accessories are included only when expressly stated for this exact part.

About ARP

Automotive Racing Products manufactures high-performance studs, bolts, nuts, washers, wheel hardware, assembly tools, and installation lubricants for engine, drivetrain, chassis, and racing applications. Thread dimensions, material, preload method, lubricant, torque, and included quantity remain exact-part specific.

Important Disclosures

• California Proposition 65 warning applies. Review the current manufacturer warning before handling or installation.

Related Parts

• Shop all ARP products
• ARP .875in OD x 7/16in ID Insert Washers (10 pack)
• ARP 01-06 6.6L GM Duramax Diesel Flywheel Bolt Kit
• ARP 01-10 6.6L GM Duramax Diesel Flexplate Bolt Kit

Frequently Asked Questions

How do I confirm the GM Duramax 6.6L Harmonic Balancer Bolt Kit fits my application?
Match the exact engine family or vehicle, component location, thread diameter and pitch, under-head length, material, strength series, and every current ARP application note.

Can I reuse the factory torque value with this ARP hardware?
Not automatically. Use ARP’s current instructions for the exact part, material, lubricant, tightening sequence, and preload method. Factory torque values may be based on different hardware and friction.

What is included with this ARP kit?
Only the studs, bolts, nuts, washers, lubricant, and tools expressly listed for this exact part number are included. Verify the required quantity before disassembly.

Installation Instructions

1. Confirm ARP part number 129-2503, the complete application, and every required supporting component before beginning work.
2. Clean and inspect all mating threads and components, then verify thread engagement, length, washers, nuts, lubricant, and required preparation before assembly.
3. Follow ARP’s current tightening sequence, lubricant instructions, torque or stretch method, and any retorque procedure for this exact part.
4. Verify clearance, preload, fastener seating, and normal component operation before returning the vehicle or engine to service.