Product Description
MAHLE 41909.03 is a complete engine set of piston rings for the 2001–2010 6.6L Duramax (LB7/LLY/LBZ/LMM). This +.030" overbore kit (4.085" bore) uses OE-grade materials and pre-lapped, standard-tension rings for fast seating and factory-correct sealing.
- Bore/Size: 4.085" (+.030")
- Ring widths: 3.0 mm (top) / 2.0 mm (second) / 3.0 mm (oil)
- Materials/face: Top ring ductile iron, plasma-moly face; second ring cast iron, chrome face; oil rails stainless steel, gas-nitride
- Configuration: Complete 8-cylinder set (drop-in, standard tension)
Fitment
- 2001–2010 Chevy Silverado/GMC Sierra 2500HD/3500HD, 6.6L Duramax LB7, LLY, LBZ, LMM (VIN 8th digit: 1 = LB7, 2 = LLY, D = LBZ, 6 = LMM)
Cross Reference Numbers
- MAHLE/Clevite: 41909.03, 41909.030, 41909030
- UPC/GTIN: 027067460813
- Ring type codes: RFK-18PF (top), BT-10UF (second), MCL-42NGRW (oil)
What’s Included
Eight (8) top rings, eight (8) second rings, and eight (8) oil ring assemblies sized for +.030" overbore.
FAQ
Is this a full engine set?
Yes. 41909.03 is a complete 8-cylinder ring set.
What bore size does .030" overuse?
4.085" (103.76 mm) for the Duramax 6.6L when using +.030" pistons.
Are the rings pre-lapped/ready to seat?
Yes — MAHLE supplies these rings pre-lapped to speed seating under normal operation.
What are the ring materials and coatings?
Top: ductile iron with plasma-moly face; second: cast iron with chrome face; oil ring rails: stainless, gas-nitride.
Will these fit LB7, LLY, LBZ, and LMM?
Yes — they’re specified for 2001–2010 6.6L Duramax (LB7/LLY/LBZ/LMM). Verify your 8th VIN digit if unsure.
