MAHLE Wave-Stopper Cylinder Head Gasket 5459X (Grade C) (2001-2016 6.6L Duramax)

Fitment

This gasket is listed for the 2001-2016 6.6L Duramax, which covers the LB7, LLY, LBZ, LMM and LML engines in Chevrolet Silverado and GMC Sierra 2500HD and 3500/3500HD pickups. It is a heavy-duty pickup part for the 6.6L; the 3.0L Duramax in the half-ton is a different engine. It is made for standard bore cylinders, so if your block has been bored oversize, this is not the gasket for it.

Duramax head gaskets are side-specific and come in thickness grades A, B and C. The grade is picked by measured piston protrusion, not by model year. This is the Grade C gasket at 1.05 mm (0.041"), so measure before you order. This listing carries two part numbers, 54597 and 54598. Confirm which one matches the bank you are working on, and if both heads are coming off, you need a gasket for each side.

If you are working on a medium-duty Kodiak or TopKick or a van, send us the VIN first. This page is written for the pickups. Verify fitment by VIN or call us before you order.

Why this part

Head gaskets are one of the known engine-level problems on the first-generation LB7. The original multi-layer steel gasket lets combustion pressure work between its layers, the aluminum heads lift under cylinder pressure, and overheating or added power speeds the whole thing up. The signs are a pressurized cooling system, a hard upper radiator hose, coolant loss with no external leak, soot or bubbles in the overflow tank, white smoke and overheating under load. It usually shows up past 100,000 miles, sooner on tuned or overheated trucks.

The later LML sees head gasket trouble less often than the LB7 and LLY, but when it happens it is hard to predict. Schultz Diesel has replaced factory gaskets at 50,000 km on stock power and seen others go past 650,000 km. Overheating is the number one cause, so find out why the old gasket failed before you put a new one in.

MAHLE's answer is its patented Wave-Stopper design. Concentric waves in the spring steel active layer around the combustion chamber let the gasket adapt to varying loads and pressures, so the seal keeps up as cylinder pressure rises and falls.

What you get

• One MAHLE Wave-Stopper cylinder head gasket, part number 54597 or 54598 depending on the variant you pick
• Sold Individually
• Manufacturer warranty: 1 Year Limited
• Not included: cylinder head bolts and gasket sealant

MAHLE lists these features:

• Direct-fit Replacement
• Multi-Layered Steel Head Gasket

Specifications

• Cylinder Bore Diameter: 106.00 mm
• Cylinder Bore Diameter: 4.17"
• Cylinder Head Gasket Material: Multi-Layered Steel
• Gasket Sealant Included: No
• Item Grade: OEM Standard
• Material: Multi-Layered Steel
• Package Quantity: 1
• Thickness: 0.041"
• Thickness: 1.05 mm
• Torque To Yield: Yes

Note: For Standard Bore Cylinders. Cylinder Head Bolts Not Included.

About MAHLE

MAHLE started in 1920 as a small engine shop in Stuttgart, Germany, and built its name on pistons. Today it makes pistons, rings, bearings, valves and gaskets for engine builders and the aftermarket. Head gaskets, head sets and complete engine gasket sets are one of the main MAHLE groups we stock. See the full MAHLE line.

Frequently asked questions

How do I know if I need Grade C?

Grade is set by measured piston protrusion, not by the year of the truck. This is the Grade C gasket at 1.05 mm. If you have not measured protrusion yet, do that first, or bring us the numbers and we will help you pick.

Can I reuse my head bolts?

Head bolts are not included, and the spec sheet lists this gasket as torque to yield. On the LB7, the factory head bolts are single-use torque-to-yield bolts, so plan on new bolts or head studs. ARP head studs are the usual upgrade when the heads come off a towed or tuned truck. On a stock-power LML, Schultz Diesel's view is that factory bolts are adequate and a healthy cooling system protects the gasket better than studs do.

Do I need both part numbers?

If both heads are coming off, yes. The 6.6L uses one gasket per head, and they are side-specific. Confirm 54597 or 54598 for each bank before you order, or call us and we will check it.

Questions on fitment? Call the shop at the number in the header. We install everything we sell.