CUMMINS 3914035 OEM EXPANSION PLUG (SIDE OF BLOCK) – RAM 5.9L 12V/24V (1989–2002)

Product Description

The Cummins 3914035 OEM Expansion Plug is the factory-correct side-of-block freeze plug used across 1989–2002 5.9L Cummins engines, including both 12-valve (6BT) and 24-valve (ISB) configurations. Designed to seal coolant passages in the block casting, this genuine Cummins plug provides the durability, corrosion resistance, and correct interference fit required to prevent coolant leaks and maintain long-term engine reliability.

Whether you're performing a complete engine rebuild, correcting a coolant leak, or replacing aged plugs during preventative maintenance, the 3914035 expansion plug ensures OE-quality sealing performance. Inferior aftermarket plugs frequently distort or lose their tension— but genuine Cummins plugs are engineered to maintain structural integrity through temperature swings, vibration, and coolant chemistry exposure.

Fitment

• 1989–1998 Dodge Ram 2500/3500 with 5.9L Cummins 12-Valve (6BT)
• 1998.5–2002 Dodge Ram 2500/3500 with 5.9L Cummins 24-Valve (ISB)
• Fits B-Series industrial, agricultural, and generator engines when 3914035 is specified (verify ESN)

Cross-Reference (Cummins-Only)

Customers replacing side-of-block plugs often service adjacent hardware. Related Cummins items on our site include:
• Cummins 3900267 Tappet Cover Bolt Grommet Seal
• Cummins 3900625 Hex Flange Head Cap Screw
• Cummins 3909395 Spring Hose Clamp (Dipstick)

FAQ

What does the Cummins 3914035 expansion plug do?

This plug seals coolant passages in the side of the block. Its primary job is to prevent coolant leakage and maintain proper pressure in the cooling system.

Should all expansion plugs be replaced during an engine rebuild?

Yes. On high-mileage 5.9L engines, freeze plugs commonly corrode over decades of coolant exposure. Replacing them during a rebuild is considered best practice to avoid future leaks.

Is 3914035 used on both 12-valve and 24-valve Cummins engines?

Correct—this OEM plug is used on 1989–2002 5.9L Cummins engines including 6BT and ISB configurations.

Is any sealant required for installation?

Many machine shops apply a thin layer of sealant for added security, but Cummins specifications rely primarily on the interference fit. Follow OEM procedures or consult your machinist.

Do aftermarket freeze plugs last as long as OEM Cummins plugs?

Aftermarket plugs often use softer material or inconsistent dimensions. Genuine Cummins plugs provide the correct hardness, corrosion resistance, and fitment for long-term reliability.

Specifications for cummins 3914035