Product Description
MAHLE B45974 is an OE-style valve stem oil seal for the 2001–2010 GM 6.6L Duramax (LB7/LLY/LBZ/LMM). These seals keep oil out of the combustion chamber for cleaner burn, reduced oil consumption, and long valve guide life.
Note: MAHLE catalog uses B45974 as the individual seal part number; the complete 16-piece set is sold as SS45974.
- Material: Metal shell with molded elastomer sealing lip
- Position: Intake/Exhaust (application may vary by head build; replace as a full set for best results)
- Quality: Made to OE specifications for durability and heat resistance
Fitment
- 2001–2004 Chevy/GMC 6.6L Duramax LB7
- 2004.5–2005 Chevy/GMC 6.6L Duramax LLY
- 2006–2007 Chevy/GMC 6.6L Duramax LBZ
- 2007.5–2010 Chevy/GMC 6.6L Duramax LMM
- Platforms: Silverado/Sierra 2500/3500; also applicable to select 6.6L medium-duty derivatives where equipped
Cross Reference Numbers
- MAHLE/ Clevite SS45974 (set of 16)
- GM/ACDelco 97212994 (kit cross), GM valve stem seal equivalents
- Industry interchange: B45974 (single), supersedes/relates to SS45974 kit listings
What’s Included
B45974 valve stem oil seal (single unit). For a full engine, order quantity 16 or use kit SS45974.
FAQ
Is B45974 a single seal or a full set?
B45974 is the individual seal number. The 16-piece set is sold as SS45974.
How many seals do I need?
The 6.6L Duramax uses 16 valve stem seals (one per valve). Replace all during head service.
Will this fit my LB7/LLY/LBZ/LMM?
Yes—B45974/SS45974 fit 2001–2010 GM 6.6L Duramax engines.
Do I need special surface prep?
Clean guides and stems, verify guide wear, and install with the proper sleeve/driver to avoid lip damage.
