Product Description
MAHLE CB-1805HK-.25MM is a performance H-Series connecting rod bearing for the 2001–2016 GM 6.6L Duramax (LB7, LLY, LBZ, LMM, LML). The .25 mm undersize shell is engineered for reground or worn journals and features the classic H-Series attributes: hardened steel back, tri-metal overlay, medium eccentricity, high crush, enlarged chamfers, and no flash plating for optimal seating in high-load builds. Sold individually; 8 required per engine.
- Engine: GM 6.6L Duramax V8 — LB7, LLY, LBZ, LMM, LML
- Series/Material: H-Series, TM-77 tri-metal with hardened steel back
- Size: 0.25 mm undersize (regrind)
- Design benefits: high load capacity, stable oil film, improved seating and fillet clearance
- Warranty: 12-month limited
Fitment
- 2001–2016 Chevrolet Silverado 2500HD/3500HD, GMC Sierra 2500HD/3500HD (6.6L Duramax)
- Also used in select 6.6L Duramax van applications (Express/Savana)
Cross Reference & Related
- MAHLE/Clevite: CB-1805HK-.25MM (this item)
- Alternates: CB-1805H-.25MM (H-Series .25 mm), CB-1805HX (H-Series extra oil clearance, STD), CB-1805P-.25MM (P-Series .25 mm)
- Application note: Many Duramax rods are stamped “A” or “B” — “B” rods use the CB-1805 family; “A” rods use the CB-1990 family.
FAQ
Will this fit my LB7/LLY/LBZ/LMM/LML?
Yes. It’s built for all 2001–2016 6.6L Duramax variants when a .25 mm undersize rod bearing is required.
How many do I need?
Eight (8) shells are required to service all connecting rods on a V8 Duramax (sold individually).
Why choose H-Series over P-Series?
H-Series emphasizes high-load performance (hardened steel back, thin overlay, high crush, enlarged chamfers). P-Series is tuned for severe rod bore close-in at very high RPM and uses a different overlay strategy.
What does .25 mm undersize mean?
It matches a crankshaft rod journal ground 0.25 mm (≈0.010″) undersize; always measure journal diameter and oil clearance during assembly.
Do these have extra oil clearance?
No. For extra clearance in standard size, use CB-1805HX (STD + .001″).
