Product Description
Upgrade your Duramax’s crankshaft security with the ARP 129-2503 BALANCER BOLT KIT. Engineered for the 2001–2019 GM 6.6L Duramax, this Pro Series damper bolt delivers superior clamping force and long-term reliability. Precision-machined threads (M18 x 1.5) and a low-profile 12-point head help ensure smooth, consistent torque and an accurate fit on performance and work trucks alike.
- Designed specifically for GM 6.6L Duramax (LB7, LLY, LBZ, LMM, LML, L5P).
- 12-point, 36mm head for confident torque application.
- Premium ARP materials and manufacturing for outstanding strength and durability.
Pair this kit with other ARP fasteners for a complete, bulletproof rotating assembly and drivetrain:
- ARP 230-2901 Flexplate Bolt Kit (2001–2010 Duramax)
- ARP 230-2801 Flywheel Bolt Kit (2001–2007 Duramax)
- ARP 230-6301 Connecting Rod Bolt Kit (2001–2010 Duramax)
- ARP 100-7532 Valve Cover Bolt Kit – Hex (LB7) / ARP 100-7531 Valve Cover Bolt Kit – 12-Point (LB7)
FAQ
WHAT ENGINES DOES ARP 129-2503 FIT?
2001–2019 GM 6.6L Duramax: LB7 (2001–2004), LLY (2004.5–2005), LBZ (2006–2007), LMM (2007.5–2010), LML (2011–2016), L5P (2017–2019).
WHAT SIZE IS THE HEAD AND THREAD?
36mm, 12-point head; M18 x 1.5 thread.
DO I NEED OTHER ARP FASTENERS FOR A BUILD?
While not required, pairing this balancer bolt with ARP flexplate/flywheel and rod bolts increases reliability. See the ARP cross-links above.
IS THERE A PROP 65 WARNING?
Yes. California residents: this product can expose you to chemicals known to the State of California to cause cancer.
Fitment Details
- GM 6.6L Duramax 2001–2019
- LB7 (2001–2004), LLY (2004.5–2005), LBZ (2006–2007), LMM (2007.5–2010), LML (2011–2016), L5P (2017–2019)
Specifications for ARP 129-2503
| UPC | 672036046835 |
|---|---|
| GTIN | 00672036046835 |
| Thread Size | M18 x 1.5 |
| Head Style / Size | 12-Point / 36mm |
| Underhead Length | 2.750 in |
| Shipping Info | Shipping calculated at checkout; package dims approx. 8" (W) x 4" (H) x 10" (D). |
| Cross Reference (ARP at CPP) | 230-2901 Flexplate Bolts; 230-2801 Flywheel Bolts; 230-6301 Rod Bolts; 100-7532 Valve Cover Bolts (Hex); 100-7531 Valve Cover Bolts (12-Point) |
| E-Codes | Not applicable |
| Prop 65 | Yes – Cancer warning for California residents. |
