Product Description
Refresh sealing and oil control on your 6.6L with the MAHLE 41909.04 Complete Piston Ring Set (.040 Over) for 2001–2010 GM Duramax LB7/LLY/LBZ/LMM. Pre-lapped plasma-moly top rings seat quickly, restore compression, and deliver long service life to performance rebuilds and heavy-duty work trucks.
Fitment
- 2001–2010 GM 6.6L Duramax V8 — LB7, LLY, LBZ, LMM
Cross-Reference / Alternatives (Mahle only)
- Mahle 41909 (STD) — complete ring set: 41909 (STD)
- Mahle S41909 (STD consumer pack): S41909 (STD)
- Mahle 41909.01 (.010 Over): 41909.01
- Mahle 41909.02 (.020 Over): 41909.02
- Mahle 41909.03 (.030 Over): 41909.03
What’s Included
- Complete engine set (rings for all 8 cylinders): top, second, and oil ring assemblies matched to +.040" overbore
Key Details
- Oversize/Bore: +.040" (approx. 4.095")
- Top ring: ductile iron, plasma-moly face
- Second ring: cast iron, chrome-faced
- Oil ring assembly: stainless steel, gas-nitride
- Axial widths: 3.0 mm / 2.0 mm / 3.0 mm
- Pre-lapped for rapid seat-in
FAQ
Will these fit all 2001–2010 Duramax codes?
Yes. They cover LB7, LLY, LBZ, and LMM 6.6L applications.
Is this a full engine set or per-cylinder?
It’s a complete engine set (rings for all eight cylinders).
Do I need to file-fit?
Always measure end-gap in your specific cylinders; file-fit to your machinist’s spec as required.
Any hone/surface finish guidance?
Use a quality plateau hone and follow MAHLE’s recommended surface finish and cleaning practices to ensure quick seating and low oil consumption.
Specifications for Mahle 41909.04
| Attribute | Value |
|---|---|
| Brand | Mahle |
| Part Number | 41909.04 (aka 41909.040) |
| UPC | 027067460820 |
| GTIN | 027067460820 |
| Engine Compatibility | 2001–2010 GM 6.6L Duramax (LB7/LLY/LBZ/LMM) |
| Ring Widths (Top/Second/Oil) | 3.0 mm / 2.0 mm / 3.0 mm |
| Bore / Oversize | ≈4.095" / +.040" |
| Package Dimensions (W×H×D) | 5.00" × 6.00" × 10.00" |
| Shipping | Free Shipping (standard ground) |
| Prop 65 | Refer to www.P65Warnings.ca.gov |
