Product Description
CUMMINS 4089258 OEM PISTON RING SET (STANDARD) – ISB 5.9L (2004.5–2007)
The genuine CUMMINS 4089258 OEM piston ring set is the correct standard bore ring pack for 2004.5–2007 ISB 5.9L engines. Using the correct OEM ring material and profile is critical for proper cylinder sealing, oil control, and long-term durability. Whether you are performing a top-end refresh or a complete engine rebuild, installing authentic Cummins piston rings ensures precise cylinder sealing and OE-grade performance.
This standard-size ring set includes the correct compression rings, oil control rings, and support rails engineered to match the factory-coated pistons used in late 5.9L ISB engines. Avoid premature blow-by, oil consumption, and low compression by choosing genuine Cummins components designed specifically for the ISB platform.
Key Features
- Genuine Cummins OEM piston ring set – not aftermarket.
- Standard bore size for OE 5.9L ISB pistons.
- Correct metallurgy and ring tension for long engine life.
- Restores compression and reduces blow-by on worn engines.
- Compatible with factory-style pistons used in 2004.5–2007 ISB engines.
Fitment Details
- Engine: ISB 5.9L Cummins
- Years: 2004.5–2007
- Applications: Dodge Ram 2500/3500 equipped with 5.9L ISB
- Notes: Standard bore only. Verify piston size and cylinder wear before ordering.
Cross-Reference & Companion Cummins Parts
Pair CUMMINS 4089258 with other genuine Cummins rebuild components available at CPP Diesel:
- CUMMINS 3957811 STANDARD PISTON – ISB 5.9L
- CUMMINS 4892735 OEM CONNECTING ROD
- CUMMINS 3949797 WRIST PIN BUSHING
- VIEW ALL GENUINE CUMMINS PARTS
Common Cummins interchange references include: 4089258, 4089257 (set variants), 4089391 (confirm by ESN).
Installation Notes
- Always measure cylinder bore taper and out-of-round before selecting ring size.
- Check ring end gap in the cylinder to confirm proper fitment.
- Install rings with the correct orientation per Cummins service guidelines.
- Hone cylinders to the proper finish when installing new rings.
Specifications for cummins 4089258
| Attribute | Value |
|---|---|
| Brand | Cummins (Genuine OEM) |
| Cummins Part Number | 4089258 |
| Bore Size | Standard (STD) for ISB 5.9L |
| Engine Compatibility | ISB 5.9L (2004.5–2007) |
| Vehicle Fitment (Common) | 2004.5–2007 Dodge Ram 2500/3500 |
| UPC | 190910479374 |
| GTIN | 190910479374 |
| Shipping Weight | Approx. 0.6 lbs |
| Shipping Method | Standard ground; expedited available |
| E-Codes / Emissions | Not emissions-critical; internal engine component |
| Prop 65 Warning | WARNING: May expose you to chemicals known to the State of California to cause cancer. See www.P65Warnings.ca.gov. |
| Country of Origin | As labeled by Cummins (varies by production batch) |
Frequently Asked Questions
WILL THESE PISTON RINGS FIT MY 2004.5–2007 5.9L CUMMINS?
Yes—CUMMINS 4089258 is the correct OEM standard bore ring set for 2004.5–2007 ISB 5.9L engines. Always verify your engine serial number for accuracy.
ARE THESE RINGS STANDARD SIZE OR OVERSIZED?
This listing is for standard bore rings. If your cylinders have been machined oversize, you will need matching oversize rings.
SHOULD I REPLACE PISTONS WHEN INSTALLING NEW RINGS?
While not always required, many rebuilders replace or inspect pistons such as the CUMMINS 3957811 standard piston when installing new rings.
DO THESE COME AS A FULL ENGINE SET?
Yes—CUMMINS 4089258 includes all piston rings required for a complete 6-cylinder 5.9L ISB rebuild.
ARE THESE GENUINE CUMMINS PISTON RINGS?
Yes, CPP Diesel supplies only authentic Cummins OEM internal engine components.
