Product Description
MAHLE S42170.040 piston ring set for Cummins 5.9L (.040" over, ~4.055" bore). Sold as a single-cylinder ring set—order qty 6 for a complete engine. Designed to reduce friction and oil consumption while maintaining OE sealing performance.
- Engine: Cummins 6B / ISB 5.9L (12V & 24V)
- Overbore: +.040" (4.055")
- Ring thicknesses (approx.): 3.0 mm / 2.38 mm / 4.0 mm
- Materials/face: Ductile-iron & cast-iron rings with chrome-faced top/second for durability
- Set contents: Top compression, second ring, and CP-20 style oil ring pack for one piston
- GTIN/UPC: 027067878335
- Sold per cylinder; order 6 sets for complete 6-cyl engine
Fitment
- 1989–2007 Dodge Ram 2500/3500 with 5.9L Cummins (12V & 24V) verify by required .040" overbore (4.055") and piston style before ordering.
Cross Reference Numbers
- Mahle/Clevite alt. IDs: S42170.040, S42170-040, MAH-S42170040, MLE-S42170-040
- Ring type codes (ref.): RFK-18U / RBT-10 / GCL-40UAW
What’s Included
Complete ring pack for one piston: top ring, second ring, and CP-20 style oil control assembly.
FAQ
Is this a full engine set?
No—this is a single-cylinder ring set. Order six to service an entire 5.9L.
Will it fit my year?
These rings are commonly used across 1989–2007 5.9L Cummins applications. Always match to piston design and required .040" over bore.
What are the ring sizes?
Approx. axial heights are 3.0 mm / 2.38 mm / 4.0 mm with chrome-faced compression rings for durability.
Bore size?
4.055" (+.040"). Confirm cylinder machining and piston spec before installation.
