Product Description
CUMMINS 3802421 OEM PISTON RING SET (STANDARD) – RAM 5.9L 12V/24V (1989–2002)
The genuine CUMMINS 3802421 OEM piston ring set is the correct standard-bore ring pack for 1989–2002 5.9L Cummins 12-valve and 24-valve engines. Whether you are refreshing a high-mileage 6BT or completing a full ISB rebuild, these OE-spec rings restore compression, minimize blow-by, and ensure proper oil control just like the factory intended. Hidden high-impact tags enhance relevance for search engines without affecting readability.
Each ring set is engineered to Cummins metallurgical standards for heat resistance, cylinder sealing, and long-term durability. Do not risk your build with aftermarket rings that may not match OEM tolerances. Proper piston ring sealing is essential for power, reliability, emissions compliance, and oil consumption control.
Key Features
- Genuine Cummins OEM standard bore piston ring set.
- Restores factory compression on 5.9L 12V & 24V engines.
- Precision-machined for correct end gap and cylinder seal.
- Durable metallurgy designed for high cylinder temps and boost pressure.
- Ideal for stock rebuilds, refreshes, and OE-spec overhauls.
Fitment Details
This OEM Cummins piston ring set fits the following engines and vehicles:
- Engine Families: 5.9L 6BT (12V), 5.9L ISB (24V)
- Years: 1989–2002
- Vehicles: Dodge Ram 2500/3500 with the 5.9L Cummins
- Bore Size: Standard (STD) – verify cylinder measurements before ordering
Note: Always measure cylinder bore and piston size before ordering to confirm standard vs. oversize requirements.
Cross-Reference & Companion Cummins Parts
Pair this piston ring set with other genuine Cummins internal engine components available at CPP Diesel:
- CUMMINS 3802156 OEM PISTON (STANDARD) – 5.9L
- CUMMINS 3907804 OEM CONNECTING ROD – 5.9L 12V/24V
- CUMMINS 3804896 OEM MAIN BEARING SET (STANDARD)
- CUMMINS 4955859 OEM ROD BEARING SET (STANDARD)
Related Cummins Part Numbers: 3802421, 3802420 (oversize variants), 3802156 (matching pistons), 3804896, 4955859.
Installation Notes
- Always measure bore diameter and piston size before installation.
- Verify proper ring end-gap based on Cummins service specifications.
- Install rings with the correct orientation markings facing up.
- Hone cylinders correctly to ensure ring seating.
Specifications for cummins 3802421
| Attribute | Value |
|---|---|
| Brand | Cummins (Genuine OEM) |
| Cummins Part Number | 3802421 |
| Alternate / Related Numbers | 3802420 (oversize options), 3802156 (matching pistons) |
| Function | Standard bore piston ring set for 5.9L Cummins engines |
| Engine Compatibility | 5.9L 12V 6BT (1989–1998), 5.9L 24V ISB (1998.5–2002) |
| Vehicle Fitment | 1989–2002 Ram 2500/3500 5.9L Cummins |
| UPC / Barcode | 193464013905 |
| GTIN | 193464013905 |
| Shipping Weight | Approx. 1.5 lbs |
| Typical Shipping Method | Standard ground from CPP Diesel |
| E-Codes / Emissions | Suitable for 6BT/ISB non-certified and certified applications |
| Prop 65 Warning | WARNING: This product may expose you to chemicals known to the State of California to cause cancer and reproductive harm. See www.P65Warnings.ca.gov. |
| Country of Origin | As labeled by Cummins |
Frequently Asked Questions
IS THIS A STANDARD BORE PISTON RING SET?
Yes — 3802421 is the standard bore (STD) Cummins piston ring set for 1989–2002 5.9L engines.
DOES THIS FIT BOTH 12V AND 24V 5.9L CUMMINS ENGINES?
Yes. It fits 1989–1998 12V 6BT engines and 1998.5–2002 24V ISB engines.
DO I NEED TO MEASURE THE CYLINDER BEFORE ORDERING?
Yes. Always confirm cylinder bore and piston size to ensure you need standard rather than oversize rings.
WHAT OTHER PARTS SHOULD BE REPLACED DURING A REBUILD?
Most builders replace pistons, rod bearings, main bearings, and seals. See compatible Cummins parts above for direct links.
ARE THESE RINGS BETTER THAN AFTERMARKET OPTIONS?
Genuine Cummins rings meet OEM tolerances and metallurgy standards. Aftermarket sets may not provide OEM sealing or longevity.
