Interstate-McBee M-4089258 Piston Ring Set – Standard Bore (04.5–07 5.9L Cummins)

OE-style standard bore piston ring set from Interstate-McBee for late-2004 (04.5) through 2007 5.9L Cummins ISB common-rail engines. Each set services one piston; order six (6) sets for a complete engine. Designed for factory bore cylinders that do not require oversize machining.

• Direct-fit replacement: Matches Cummins 4089258 application for ISB/QSB platforms.
• STD bore: For unbored cylinders (nominal 4.020" / 102.0 mm).
• Per-piston packaging: One set per cylinder streamlines service; buy 6 for full engine.
• Aftermarket value: Interstate-McBee quality at a lower cost than OE-boxed rings.

Specifications

Vehicle Fitment

Fitment can vary by CPL/ESN—verify by engine serial number (ESN) for best results.

• Dodge Ram 2500/3500 – 5.9L Cummins ISB (Common Rail)
  • Model years: 2004.5–2007 (late-2004 HO update through 2007)
• Industrial: Select Cummins ISB/QSB 5.9L applications (ESN confirmation required).

Note: Some early 2003–2004 common-rail engines use a different ring set. Confirm by ESN before ordering.

Install Tips

• Measure cylinder taper/out-of-round; standard bore rings are not a fix for worn cylinders.
• Always check and set ring end-gaps per Cummins service specifications.
• Stagger ring gaps as specified; clean ring lands thoroughly before installation.

Why Buy From CPP Diesel

• ESN-verified fitment support from real diesel techs
• Fast shipping, hassle-free returns
• Matched add-ons: ring compressor, head & gasket kits, pistons

FAQ