Product Description
CUMMINS 3900068 OEM RING DOWEL (14MM) – CYLINDER HEAD / MAIN BEARING CAP – 5.9L & 6.7L CUMMINS
The genuine CUMMINS 3900068 OEM ring dowel is the factory-correct 14mm alignment dowel used on both 5.9L and 6.7L Cummins engines. This precision-machined locating dowel ensures accurate alignment of the cylinder head and main bearing caps during assembly and is required any time major engine components are replaced or rebuilt.
Worn, missing, or damaged dowels can lead to serious issues such as improper head gasket sealing, bearing misalignment, and accelerated wear. Replacing them with authentic Cummins hardware ensures proper index, fitment, and clamping integrity throughout the engine structure.
Key Features
- Genuine Cummins OEM 14mm ring dowel – exact factory dimensions and metallurgy.
- Critical alignment component for cylinder head and main bearing cap installation.
- Required for proper engine rebuilds, head gasket replacement, machine work, and bottom-end service.
- Works on all 5.9L & 6.7L Cummins B-series engines, including Ram 2500/3500 applications.
- Prevents misalignment-related failures such as bearing wear or head gasket issues.
Fitment Details
- Engine: 5.9L Cummins (1989–2007), 6.7L Cummins (2007.5–present)
- Applications: Cylinder head alignment, main bearing cap alignment
- Common Vehicles: 1989–2024 Ram 2500 / 3500 with 5.9L or 6.7L Cummins
- Size: 14mm ring dowel
Always verify with VIN/ESN to ensure correct dowel sizing for your specific build.
Cross-Reference & Companion Cummins Parts
Pair this dowel with other genuine Cummins hardware commonly used during top-end and bottom-end engine service:
- CUMMINS 3930406 CYLINDER HEAD GASKET – 5.9L CUMMINS
- CUMMINS 4896158 CYLINDER HEAD GASKET – 6.7L CUMMINS
- CUMMINS 4891178 MAIN BEARING SET – 6.7L CUMMINS
More Cummins hardware available in our catalog: VIEW ALL CUMMINS GENUINE PARTS
Specifications for cummins 3900068
| Attribute | Value |
|---|---|
| Brand | Cummins (Genuine OEM) |
| Cummins Part Number | 3900068 |
| Function | 14mm ring dowel used for cylinder head and main bearing cap alignment |
| Engine Compatibility | 5.9L Cummins (1989–2007), 6.7L Cummins (2007.5–present) |
| Vehicle Compatibility | 1989–2024 Ram 2500/3500 with 5.9L or 6.7L Cummins |
| Material | Hardened steel (OEM spec) |
| UPC | 193807513069 |
| GTIN | 193807513069 |
| Shipping Weight | Approx. 0.05 lb |
| Typical Shipping Method | Standard ground; ships small-parcel |
| E-Codes | Used across multiple B-series emissions families; verify by ESN |
| Prop 65 Warning | WARNING: This product can expose you to chemicals including metallic residues known to cause cancer and reproductive harm. More information at www.P65Warnings.ca.gov. |
| Country of Origin | As labeled by Cummins (varies by production batch) |
Frequently Asked Questions
WHERE IS THE CUMMINS 3900068 RING DOWEL USED?
This 14mm dowel is used for cylinder head alignment and main bearing cap alignment on 5.9L and 6.7L Cummins engines.
DO I NEED NEW DOWELS WHEN INSTALLING A NEW CYLINDER HEAD?
Yes. Cummins recommends replacing dowels during major service to ensure precise alignment and proper head gasket sealing.
ARE THESE SOLD INDIVIDUALLY?
Yes. Each 3900068 dowel is sold individually. Order the quantity required for your engine configuration.
WILL THIS FIT BOTH 5.9L AND 6.7L CUMMINS?
Yes. The 14mm OEM dowel is used on both platforms. Always verify your ESN for absolute accuracy.
IS THIS A GENUINE CUMMINS PART?
Yes. CPP Diesel sells only authentic Cummins OEM hardware for this part number.
