CUMMINS BSERIES TURBOCHARGED CERAMIC CHROME TOP RING RING SET CHROME

The MAHLE/Clevite S42170.040 piston ring set is designed for rebuilt 1989-2007 5.9L Cummins engines that have been bored to +.040" (approximately 4.055"). These rings feature engineered geometry and chrome-faced compression rings to help restore lost compression, minimize blow-by, and control oil consumption.

This set includes a complete ring pack for a single piston, consisting of the top compression ring, second ring, and oil control assembly. It is crucial to confirm the finished bore and piston groove specifications before installation and file-fit the end gaps according to Cummins/Mahle specifications. An appropriate 4.055" ring compressor should be used during installation, with gaps oriented per the service manual.