Product Description
The CUMMINS 3973512 OEM ENGINE OIL CAP O-RING is designed for 1998.5-2025 5.9L and 6.7L Cummins diesel engines. This genuine Cummins sealing O-ring helps maintain a proper seal between the engine oil fill cap and valve cover, preventing oil seepage, contamination, and crankcase leakage.
Use this part when replacing a worn, flattened, cracked, or leaking oil cap seal. A fresh O-ring helps ensure proper sealing and keeps dirt, moisture, and debris from entering the engine. Always verify fitment by part number and engine application before ordering.
FEATURES
- Genuine Cummins OEM engine oil cap O-ring
- Direct-fit replacement sealing component
- Helps prevent oil seepage around the fill cap
- Maintains proper crankcase sealing
- Resists heat, oil, and engine compartment contaminants
- Ideal for routine maintenance and oil cap service
FITMENT
- 1998.5-2002 Dodge Ram 2500/3500 5.9L Cummins 24-Valve
- 2003-2007 Dodge Ram 2500/3500 5.9L Cummins Common Rail
- 2007.5-2025 Ram 2500/3500/4500/5500 6.7L Cummins
- Select Cummins industrial, commercial, and agricultural applications
WHAT'S INCLUDED
- 1 Cummins 3973512 OEM Engine Oil Cap O-Ring
CROSS-REFERENCE AND RELATED PRODUCTS
- Cummins 3973512
- Cummins Engine Oil Fill Cap Assemblies
- Valve Cover Service Components
- Crankcase Ventilation System Components
SPECIFICATIONS
- Manufacturer: Cummins
- Part Number: 3973512
- Part Type: Engine Oil Cap O-Ring
- Material: Oil-Resistant Elastomer
- Engine Compatibility: 5.9L Cummins, 6.7L Cummins
- Fitment Years: 1998.5-2025
- Vehicle Application: Dodge Ram / Ram 2500, 3500, 4500, 5500
- Condition: New OEM Cummins
- Installation Type: Direct Replacement
FAQ
Will this part fit my truck?
This O-ring fits many 1998.5-2025 5.9L and 6.7L Cummins applications. Always verify fitment using your part number and engine application before ordering.
Is this a genuine Cummins seal?
Yes. Cummins 3973512 is a genuine OEM Cummins engine oil cap O-ring.
What does this O-ring do?
This seal creates a leak-resistant connection between the engine oil fill cap and valve cover while helping keep contaminants out of the engine.
When should the oil cap O-ring be replaced?
Replace the O-ring if it becomes hard, flattened, cracked, damaged, or if oil seepage is present around the oil fill cap.
Can a bad oil cap seal cause oil leaks?
Yes. A worn or damaged O-ring can allow oil mist and seepage around the oil fill cap area and may contribute to crankcase contamination.
Do I need any related parts?
Inspect the oil fill cap, valve cover sealing surfaces, crankcase ventilation components, and surrounding seals during service and replace worn components as necessary.
