Keep coolant sealed where the thermostat meets the engine with the MAHLE Engine Coolant Thermostat Gasket C31858. It installs as a direct-fit replacement across Dodge Ram and Ram heavy-duty trucks, sealing the joint between the thermostat housing and the engine so coolant stays contained and the cooling system holds pressure. Fits the 2003-2008 Dodge Ram 2500 (L6-5.9L) and 2007-2010 Dodge Ram 2500 (L6-6.7L), the 2003-2007 Dodge Ram 3500 (L6-5.9L) and 2007-2010 Dodge Ram 3500 (L6-6.7L), the 2008-2010 Dodge Ram 4500 and 5500 (L6-6.7L), and the 2011-2024 Ram 2500, 3500, 4500, and 5500 (L6-6.7L) — see the Buyer's Guide tab for the full list.
The listed applications use one gasket. Signs the original may need replacing include coolant weeping or dripping at the thermostat housing and a low-coolant condition. Manufacturer part number C31858.
This part cross-references / interchanges with the following part numbers:
What does this gasket do?
It seals the joint between the thermostat housing and the engine, helping keep coolant contained and the cooling system holding pressure on the listed applications.
What is the gasket made of?
The gasket material is molded rubber, which conforms to the sealing surfaces at the thermostat housing.
Which vehicles does it fit?
It fits Dodge Ram and Ram 2500, 3500, 4500, and 5500 trucks with the L6-5.9L or L6-6.7L engine, from 2003 through 2024. See the Buyer's Guide tab for the full list.
How many gaskets do I need?
The listed applications use one gasket, and this listing is for one. Confirm the quantity for your specific vehicle in the Buyer's Guide.
What are signs this gasket may need replacing?
Coolant weeping or dripping at the thermostat housing and a low-coolant condition can indicate the gasket may need replacing. Diagnose the source of the leak before replacing.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
