Product Description
The Cummins 3940059 OEM Camshaft Bushing (Thick) is a genuine, heavy-wall camshaft support bushing engineered for 5.9L and 6.7L ISB Cummins engines from 1997.5–2018. This reinforced bushing provides added structural stability for the cam bore, improving support, reducing wear, and maintaining consistent lubrication to the camshaft journals. Its thicker-wall design is used in specific ISB engine builds requiring enhanced strength and long-term reliability.
Whether performing a top-tier engine rebuild, correcting cam-bore wear, or restoring an ISB engine to OEM-level precision, the 3940059 thick camshaft bushing delivers unmatched durability and tight machining tolerances only genuine Cummins components can guarantee.
Fitment
- 1997.5–2002 5.9L 24-Valve ISB Cummins
- 2003–2007 5.9L Common Rail ISB Cummins
- 2007.5–2018 6.7L ISB Cummins (Dodge/Ram & medium-duty platforms)
- Industrial, agricultural, and construction B-Series / ISB engines (verify by ESN)
Important: Cam bushings vary by ESN and block machining requirements. Always verify your engine serial number (ESN) before ordering.
Cross-Reference (Cummins-Only)
Additional Cummins valvetrain & camshaft-related components:
• Cummins 3903924 OEM Timing Pin – 5.9L
• Cummins 3904408 OEM Valve Stem Guide – 60.50mm
• Cummins 3904409 OEM Valve Stem Guide – 51.75mm
FAQ
What is the purpose of the Cummins 3940059 thick camshaft bushing?
This OEM bushing supports the camshaft and maintains proper oiling while providing enhanced structural stability for high-load ISB applications.
How do I know if I need the “thick” bushing?
Certain ISB blocks require the thick-wall version based on machining specs. Verify by ESN or match to your existing OE bushing.
Is this bushing compatible with performance camshafts?
Yes — the thick OEM bushing is commonly used in both stock and mild performance builds, provided clearances are measured during installation.
Does this bushing require machining?
Yes. Cam bushings must be professionally installed and line-bored to Cummins specifications for proper camshaft oiling and alignment.
Specifications for cummins 3940059
| Specification | Value |
|---|---|
| Brand | Cummins Genuine Parts |
| Part Number | 3940059 |
| Component Type | Thick Camshaft Bushing |
| UPC | Not Published |
| GTIN | Not Published |
| Cross Reference | Used across ISB cam bore assemblies (ESN-specific) |
| E-Codes | N/A |
| Shipping Weight | 0.20 lbs |
| Package Dimensions | 2 x 2 x 2 in |
| Prop 65 Warning | Not Applicable |
