Product Description
Genuine Cummins
Cummins 4089258 — Piston Ring Set (Standard Bore) for ISB 5.9L
MPN: 4089258 | Also Known As: piston rings, ring set | Application: ISB 5.9L common-rail (see fitment)
Why This Part
- ✓ Genuine Cummins standard-bore ring pack for factory seal & longevity.
- ✓ Direct-fit for 2004.5–2007 5.9L ISB (common-rail) refreshes and rebuilds.
- ✓ Restores proper compression & oil control when bores remain standard.
- ✓ OE materials & profiles for stable break-in and ring life.
OE Fit Standard Bore 6 Sets / Engine
Quick Specs
| Type | Piston Ring Set (Standard Bore) |
|---|---|
| OE Part # | 4089258 |
| Qty Required | 6 sets per engine (sold individually; 1 set per cylinder) |
| Pair With | ARP 900-0200 ring compressor (4.020") and OE gasket kits as needed |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 2004.5–2007 | Ram 5.9L ISB (24V Common-Rail) | Ram 2500/3500 |
Industrial/Off-Highway: Used primarily on EPA02-era ISB/QSB 5.9 applications—verify by ESN before ordering.
Often Paired With
- Piston Kits: 4089669 (Std), 4089670 (.020")
- Lower Engine Gasket Kit: 4089173
- Head Gaskets: 3958644 (Thin), 3958645 (Thick)
- Ring Compressor: ARP 900-0200 (4.020" bore)
What’s In The Box
- (1) Genuine Cummins Piston Ring Set (4089258) — for one cylinder
- Order 6 sets for a complete 5.9L engine
Install Tips
- Measure bores; confirm standard size and roundness; hone for proper surface finish.
- File-fit ring end gaps if required; orient per Cummins service manual.
- Use clean assembly lube and a quality ring compressor; verify free ring movement.
FAQ
WILL THIS FIT MY 2004.5–2007 5.9L CUMMINS RAM?Yes—these are the OE standard-bore rings for 2004.5–2007 5.9L ISB common-rail (verify by VIN/ESN).
HOW MANY DO I NEED FOR A FULL REBUILD?Order 6 sets (one per cylinder) for a complete engine.
ARE THESE STANDARD OR OVERSIZE RINGS?Standard bore. If your cylinders are bored oversize, select the matching oversize ring set instead.
WHAT TOOLS DO I NEED?A 4.020" ring compressor (e.g., ARP 900-0200) and standard engine rebuild tools are recommended.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins ring set 4089258 for factory fit and durability.
