Product Description
MAHLE CB-1990P-.25MM is a P-Series connecting rod bearing for the 2001–2016 GM 6.6L Duramax (LB7/LLY/LBZ/LMM/LML). This .25 mm undersize bearing is designed for cranks that have been ground/polished to undersize and is intended for rods marked with “A”. Tri-metal construction with a hardened steel back delivers high crush for secure seating and durability under load.
- Size: .25 mm undersize (for machined crank journals)
- Series/Material: P-Series tri-metal with TM-77 overlay; hardened steel back
- Use: Replacement/Performance rebuilds; reduces overlay fatigue (“tracking”)
- Sold individually; one bearing position per listing. Typical V8 requires 8 rod bearing positions (“A” + “B” shells by rod).
- GTIN/UPC: 027067970992; Use with connecting rods stamped “A”.
Fitment
- 2001–2016 Chevrolet/GMC 6.6L Duramax: LB7, LLY, LBZ, LMM, LML (Silverado/Sierra 2500HD–3500HD, Express/Savana 2500–3500)
Cross-Reference & Related
- Standard size “A” shell: MAHLE/Clevite CB-1990P (STD)
- .50 mm undersize “A” shell: MAHLE/Clevite CB-1990P-.50MM
- “B” shell (companion piece): MAHLE/Clevite CB-1805P (sizes STD/.25/.50)
- Thrust washers: MAHLE/Clevite TW-610S
- Main bearings (.25 mm undersize): MAHLE/Clevite MS-2218P-.25MM
FAQ
Will this fit all 2001–2016 Duramax engines?
Yes. It’s listed for LB7/LLY/LBZ/LMM/LML 6.6L Duramax applications from 2001–2016. Verify undersize is correct for your machined crank.
How do I know if I need the “A” or “B” shell?
Duramax rods are marked “A” and “B.” This part is for rods marked “A.” The companion “B” shell is CB-1805P in the matching size.
Is crank machining required?
Yes for undersize bearings. .25 mm bearings require a properly ground and finished crankshaft journal.
Is this sold as a set of 8?
No—sold individually. Order the required quantity to service all eight rod journals (A/B shells per rod).
What else should I replace during the job?
Inspect/replace main bearings (MS-2218P series) and thrust washers (TW-610S), and use new lower-end gaskets/seals as needed.
