Mahle S41940.040 Engine Piston Ring Set

Product Overview

Mahle S41940.040 is a premium engine piston ring set built for 3.7795-inch bore applications with a 0.040-inch oversize. It is engineered for Ford Super Duty gas engine rebuilds where ring sealing, oil control, and reduced friction matter.

Compatible With Ford F-250 Super Duty, Ford F-350 Super Duty, Ford F-450 Super Duty, Ford F-550 Super Duty, Ford E-350 Super Duty, Ford E-450 Super Duty, Ford E-350 Club Wagon, and Ford Excursion applications listed below. Part number S41940.040 is also cross-referenced to 1845605C92040 for the same application.

Key Features

• Premium-grade piston ring set for engine rebuild service
• 0.040-inch oversize for matched bore correction
• Plasma-moly face coating for improved wear resistance
• Carbon steel top ring, ductile iron second ring, and cast iron oil ring assembly
• Two-piece oil ring assembly for controlled oil management
• Designed to reduce friction, ring mass, and engine oil consumption

Detailed Description

Mahle S41940.040 uses advanced ring materials and coatings to support consistent cylinder sealing and oil control in rebuild applications. The top ring uses carbon steel with a plasma-moly face coating, while the second ring and oil ring assembly use cast iron-based construction for durability and stable operation. This combination is suited to Ford F-250 Super Duty, Ford F-350 Super Duty, and related Super Duty platforms that require a 0.040-inch oversize ring package.

The ring set reflects Mahle’s OE-driven engineering approach, with a focus on lower friction, reduced oil consumption, and longer service life. Use S41940.040 when the cylinder bore has been machined for the specified oversize and the engine requires premium replacement rings. Part number S41940.040 should be matched carefully to the listed bore and fitment data before assembly.

What It Is Used For

• Restoring cylinder compression after engine wear
• Reducing oil consumption caused by worn rings
• Improving ring seal in rebuilt engines
• Replacing damaged or fatigued piston rings during overhaul
• Supporting proper combustion sealing in oversize bore applications

Installation Notes and Tips

Verify bore diameter, oversize specification, and ring end-gap requirements before installation. This part is listed for 0.040-inch oversize applications only, so cylinder machining and piston compatibility must match the engine build. Follow the engine builder’s service procedures for ring orientation, gap placement, and lubrication during assembly.

Quality Assurance

Mahle positions this piston ring set as an OE-driven premium component with advanced ring technology focused on friction reduction, oil control, and service life. The part number S41940.040 is built to the specifications shown in the product data and fitment listing.