MAHLE S41909 Piston Ring Set (Standard) (2001-2010 6.6L Duramax)
Fits: Chevrolet • GMC
Diesel Dollars is Southern Diesel Supply's Loyalty Program. Purchasing with Us Earns you 1 Point for every 1 Dollar spent to use for future buys!
By ordering the MAHLE S41909 Piston Ring Set (Standard) (2001-2010 6.6L Duramax) you will earn 77 DIESEL DOLLARS in your SDS Fuel Tank!
The MAHLE S41909 is a standard-size piston ring set for the 2001-2010 GM 6.6L Duramax: LB7, LLY, LBZ and LMM. Each set holds the rings for one cylinder, so a complete engine takes eight. You buy it when the engine is apart for a rebuild and you want rings built from OE materials to stock specifications.
Fitment
Listed for the 2001-2010 6.6L Duramax in Chevrolet Silverado and GMC Sierra heavy-duty pickups:
- LB7: 2001-2004
- LLY: 2004.5-2005
- LBZ: 2006-2007
- LMM: 2007.5-2010
That covers the Silverado and Sierra 2500HD and the one-ton trucks. On the early trucks the one-ton was sold as the 3500; the HD badge on the 3500 came with the 2007 GMT900 redesign. The LB7 was never offered in a 1500 or 1500HD. This listing stops at 2010, so for a 2011-2016 LML, call us.
This is the Standard set, sized for cylinders at the factory bore. If the block has been bored oversize, you need rings matched to the oversize pistons instead. The 2003-2004 Kodiak and TopKick C4500/C5500 also used the LB7, under the LRY medium-duty power option. This page is written for the pickups, so check a medium-duty truck with us first. Verify fitment by VIN or call us.
Why this part
When a Duramax comes apart for a rebuild, new rings are part of putting it back together. The S41909 is made to meet stock specifications and constructed from OE materials, so the rebuilt engine keeps factory performance. It suits an engine going back together at the factory bore and stock specs.
The LB7 bottom end is strong. Trouble starts above roughly 550-600 rwhp, where pistons can crack, head gaskets fail and rods bend. Below that, if an LB7 is on the stand, find out what put it there before fresh rings go in.
Two LB7 patterns to rule out first. Leaking under-cover injectors can run fuel past the injector cup seal into the head oil drains and the crankcase; you see a rising oil level and a diesel smell on the dipstick. Head gasket failure shows up as a pressurized cooling system, coolant loss with no external leak, white smoke and overheating under load. New rings will not fix either one.
What you get
One MAHLE S41909 piston ring set, Standard size, for one cylinder. MAHLE lists these features:
- OE Quality
- Maintains a Factory Performance
Application Notes: Contains rings for single cylinder. Must order qty 8 for complete set.
About MAHLE
MAHLE opened as a small engine shop in Stuttgart, Germany, in 1920, and pistons are the product that put it on the map. Today it also makes rings, liners and bearings, and diesel shops have leaned on those lines for years. For the Duramax we carry MAHLE pistons and piston-with-rings assemblies in standard and oversize bores; see the MAHLE collection.
Frequently asked questions
How many ring sets do I need?
Eight for a complete engine. Each S41909 contains the rings for a single cylinder, so order quantity 8 to do the whole V8.
Will these work in a block that has been bored oversize?
No. This is the Standard set for factory-bore cylinders. An oversize bore needs rings that match the oversize pistons. Call us with the bore size and we will match it.
Does one part number cover both an LB7 and an LMM?
Yes. The S41909 is listed for the 2001-2010 6.6L Duramax across the LB7, LLY, LBZ and LMM. Confirm the engine on your VIN before you order.
Questions on fitment? Call the shop at the number in the header. We install everything we sell.
Diesel Dollars is Southern Diesel Supply's Loyalty Program. Purchasing with Us Earns you 1 Point for every 1 Dollar spent to use for future buys!
By ordering the MAHLE S41909 Piston Ring Set (Standard) (2001-2010 6.6L Duramax) you will earn 77 DIESEL DOLLARS in your SDS Fuel Tank!