Product Description
Genuine Cummins
Cummins 4089669 — Standard-Bore Engine Piston Kit (5.9L ISB)
MPN: 4089669 | Also Known As: piston & ring kit (STD) | Oversize Alternatives: 4089670 (.020"), 4089671 (.040")
Why This Part
- ✓ OE-quality piston kit for 2004.5–2007 5.9L ISB common-rail builds.
- ✓ Complete STD kit — piston, ring set, wrist pin, and retaining clips.
- ✓ Direct-fit geometry for proper sealing and durability.
- ✓ Sold individually — order 6 kits for a full engine set.
OE Fit Standard Bore Sold Individually
Quick Specs
| Type | Engine piston kit (standard bore) |
|---|---|
| OE Part # | 4089669 (STD) · 4089670 (.020") · 4089671 (.040") |
| Includes | Piston, ring set, wrist pin, (2) retaining clips |
| Qty Required | 6 per engine (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 2004.5–2007 | 5.9L ISB (24V Common-Rail) | Ram 2500/3500 |
Industrial/Off-Highway: Also used on select non-certified ISB/QSB 5.9 applications—verify by ESN before ordering.
Often Paired With
- Upper head gasket set (’03–’07 5.9L CR) · common gaskets: 3958644 (thin) / 3958645 (thick)
- Replacement ring set (STD) 4089258 (if spares needed)
- Wrist pin 3934047 & retaining clips 3920691 (spares)
- Rod & main bearings, cylinder hone, assembly lube
What’s In The Box
- (1) Standard-bore piston
- (1) Piston ring set
- (1) Wrist pin
- (2) Wrist pin retaining clips
Install Tips
- Match bore size to cylinder measurement and hone finish; maintain proper ring end gap.
- Verify piston orientation and ring placement; use assembly lube and torque to spec.
- Always confirm ESN/CPL for component compatibility in mixed-year builds.
FAQ
WILL THIS FIT MY 2004.5–2007 5.9L CUMMINS RAM?Yes—this STD piston kit targets 2004.5–2007 5.9L ISB common-rail Ram 2500/3500. Always confirm by VIN/ESN or CPL.
WHAT’S INCLUDED IN THE 4089669 KIT?Piston, rings, wrist pin, and retaining clips—sold as a single-cylinder kit. Order six for a complete engine.
DO YOU HAVE OVERSIZE OPTIONS?Yes—.020" oversize is 4089670 and .040" oversize is 4089671. Measure cylinders to select the correct size.
IS THIS A GENUINE CUMMINS PART?Yes—this is an OE Cummins piston kit matched to the 2004.5–2007 5.9L ISB application.
WILL THIS WORK ON EARLY 2003–EARLY 2004 5.9L ENGINES?Those use a different piston design. Verify your ESN/CPL to ensure you’re ordering the correct kit.
