Mahle OE Standard Bore Piston with Rings Set of 6 for 1989-1998 Cummins 5.9L 12-Valve

OE-Quality Pistons and Rings for the 1989-1998 Cummins 5.9L 12-Valve 6BT Engine Rebuild

The Mahle 2243523WR is a complete set of six standard-bore pistons with rings for the 1989-1998 Dodge Ram 2500 and 3500 equipped with the Cummins 5.9L 12-valve 6BT engine. Mahle supplies piston components to Cummins as an OEM supplier, and this set is engineered to the same dimensional tolerances and material standards as original equipment. The marine-style combustion bowl design supports clean combustion and consistent heat management under load. The cast aluminum pistons feature expansion-controlled skirt geometry for stable piston-to-wall clearance through the full operating temperature range, and the floating 40 mm wrist pins allow free rotation to reduce pin bore wear. Each piston ships with a matched ring set providing proper ring loading and oil control from the first startup.

Key Features

• Complete set of 6 standard-bore pistons with matched ring sets for the 1989-1998 Cummins 5.9L 12-valve 6BT
• Marine-style combustion bowl design for consistent combustion quality and heat management under towing and load conditions
• Cast aluminum construction with expansion-controlled skirt geometry for stable wall clearance across the full operating temperature range
• Floating 40 mm wrist pins reduce pin bore wear and are included with the set
• OE-specification ring pack provides proper ring loading and oil control from initial startup
• Mahle is a Cummins OEM supplier; this set meets the same dimensional and material standards as factory components
• Standard bore (STD), 4.016 in (102 mm), suitable for engines with unworn or freshly honed cylinders at standard dimension

Vehicle Fitment

Specifications

What's Included

• 6x cast aluminum pistons (standard bore, marine-style bowl)
• 6x matched ring sets (compression and oil control rings)
• 6x floating 40 mm wrist pins
• 6x wrist pin retaining clips

About Mahle

Mahle is a German-founded automotive systems supplier and one of the largest manufacturers of engine components in the world. The company supplies pistons, rings, bearings, and cylinder components directly to OEM engine builders including Cummins, Ford, GM, and Daimler. Mahle's aftermarket division produces the same components to the same standards as the OEM line, making their replacement piston sets a direct match for engines originally built with Mahle components.

Related Parts on Our Site

• Engine Rebuild Components

Frequently Asked Questions

The Mahle 2243523WR is a complete set of six standard-bore cast aluminum pistons with rings, wrist pins, and retaining clips for the 1989-1998 Cummins 5.9L 12-valve 6BT engine. Mahle is an OEM supplier to Cummins and manufactures this set to the same dimensional tolerances and material specifications as factory components.

This piston set fits 1989-1998 Dodge Ram 2500 and Ram 3500 trucks equipped with the 5.9L Cummins 12-valve 6BT diesel engine. It does not fit the 24-valve ISB engines used in 1998.5 and later Ram trucks. Confirm your engine generation by checking the valve cover; 12-valve engines have a single rocker arm per cylinder visible from the top.

The 2243523WR is a standard bore (STD) set for a cylinder diameter of 4.016 in (102 mm). It is designed for engines with cylinders that measure at standard diameter, either because they are unworn or have been freshly honed back to standard. If your cylinders are worn or have been bored oversize, Mahle offers the same piston in .020, .030, and .040 oversize variants.

Yes. The 2243523WR includes a complete set of six pistons along with matched compression and oil control rings, 40 mm floating wrist pins, and wrist pin retaining clips. No additional ring set purchase is required.

The marine-style combustion bowl (also called QSB-style) is a specific piston crown geometry used on early 12-valve 6BT engines. The bowl shape influences how the fuel spray pattern interacts with the combustion chamber. On early 12-valve engines, the marine bowl design supports cleaner combustion and more consistent heat rejection under sustained load compared to alternative bowl profiles, which is why it is used in both factory rebuilds and performance-oriented street builds.

Yes. A standard bore piston set does not replace machine shop work on a worn engine. Before installation, the block should be inspected and the cylinders measured. If cylinders are within standard tolerance, a light hone to refresh the crosshatch pattern is typically required. If cylinders are out of round or oversized, the block must be bored and honed to the appropriate oversize before a standard bore set can be used. Ring end gaps should be measured and adjusted to Cummins specification before installation.

Yes. This product is subject to California Proposition 65. Engine components including pistons and rings contain materials known to the State of California to cause cancer, birth defects, or other reproductive harm. Always handle with care, avoid ingesting dust or residue, and wash hands thoroughly after installation.

The 2243523WR is an OE-specification cast aluminum piston set. It is appropriate for stock rebuilds, daily drivers, and moderate towing applications. For engines running significantly increased fuel delivery, elevated boost, or extended high-load operation, forged piston sets offer greater fatigue resistance. Consult your engine builder if you plan to modify fueling or boost beyond stock parameters.

Installation Instructions

1. Drain coolant and engine oil. Remove the cylinder head, oil pan, and timing cover as required to access the pistons and connecting rods.
2. Remove each connecting rod cap and carefully push each piston and rod assembly out through the top of the block. Keep rod caps matched to their rods and mark orientation before disassembly.
3. Clean and inspect the block. Measure each cylinder bore for diameter, taper, and out-of-round using a dial bore gauge. Hone or bore as required to achieve standard clearance specification.
4. Measure piston-to-wall clearance for each new piston in its assigned bore. Clearance should meet Cummins specification for the 5.9L 6BT before proceeding.
5. Measure ring end gap for each ring in its assigned bore. Adjust by filing the ring ends as needed to achieve Cummins specification for each ring groove position.
6. Lubricate the cylinder walls, wrist pin bores, and piston skirts with clean engine oil. Install wrist pins and retaining clips. Install rings using a ring expander tool, staggering end gaps per Cummins specification.
7. Compress the ring pack using a proper ring compressor and install each piston and rod assembly into the cylinder. Ensure the piston orientation and connecting rod orientation are correct for the 1-5-3-6-2-4 firing order.
8. Install rod caps and torque rod bolts to Cummins specification. Reassemble the engine in reverse order. Fill with fresh engine oil and coolant. Start the engine and follow a proper break-in procedure before sustained high-load operation.

WARNING: This product can expose you to chemicals including lead and lead compounds, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.p65warnings.ca.gov.