Product Description
The Cummins 3921640 OEM Valve Stem Seal delivers precise oil control and long-term durability for your 1989–1998 Ram 5.9L 12-Valve Cummins. Designed to prevent excessive oil consumption and protect valve guides, this genuine Cummins component is engineered for exact fit and consistent performance.
FITMENT
- 1989–1993 Dodge Ram 2500/3500 – 5.9L 12-Valve Cummins (6BT)
- 1994–1998 Dodge Ram 2500/3500 – 5.9L 12-Valve Cummins (6BT)
CROSS-REFERENCE / ALTERNATIVE CUMMINS PARTS
- Cummins 3901097 Valve Seal (placeholder)
- Cummins 3919330 Valve Seal (placeholder)
These links will be updated to working CPPDiesel.com Cummins OEM URLs once you provide them.
WHY CHOOSE OEM CUMMINS VALVE STEM SEALS?
- Direct-fit seal designed specifically for 6BT engines
- Maintains proper lubrication control
- Prevents oil burning & valve fouling
- Meets OEM heat, wear, and chemical-resistance standards
FAQ
How many valve stem seals does a 5.9L 12-Valve engine require?
A 12-Valve 6BT Cummins requires 12 total seals—one per valve.
Should valve stem seals be replaced during a top-end or head gasket job?
Yes. Replacing seals during any head removal ensures proper oil control and prevents smoking or oil consumption issues.
Is this seal compatible with aftermarket valve guides?
Yes, as long as the guide is sized for OEM-spec 6BT valve hardware.
Specifications for CUMMINS 3921640
| Attribute | Value |
| Brand | Cummins Genuine Parts |
| Part Number | 3921640 |
| GTIN | Not Published |
| UPC | Not Published |
| Cross Reference | 3901097, 3919330 |
| E-Codes | None |
| Shipping Info | Ships via USPS/UPS in small protected packaging |
| Prop 65 | No California Proposition 65 warning required |
