Cummins 6CT Engine Parts – Crankshaft and Related Components Catalog

The Cummins 6CT 8.3 engine is one of the most proven and widely used diesel engines across marine, industrial, and heavy-duty equipment. Known for its balance of durability, performance, and serviceability, it relies heavily on the strength and precision of its crankshaft assembly. The crankshaft is the heart of the rotating assembly, and keeping it in excellent condition ensures smooth operation, fuel efficiency, and long-term reliability.

At Diesel Pro Power, we provide high-quality Cummins 6CT crankshafts, bearings, seals, vibration dampers, and expansion plugs, trusted by over 40,000 satisfied customers worldwide. This section highlights the available Cummins 6CT crankshafts and supporting parts designed for engine rebuilds and overhauls.

The Role of the Crankshaft in the Cummins 6CT

The crankshaft in the Cummins 6CT transforms the linear energy of piston motion into rotational energy that powers the flywheel and drives the machine or vessel. It is subjected to extreme forces during every combustion cycle, making its strength, balance, and lubrication vital to engine health.

A properly functioning crankshaft ensures:

• Smooth power delivery with reduced vibration.

• Reliable bearing support and oil film integrity.

• Consistent engine timing and balance.

• Prevention of premature wear in the rotating assembly.

When replacing or overhauling the Cummins 6CT, selecting the right crankshaft and related components is critical to restoring original performance.

Crankshaft Assemblies for Cummins 6CT

Two Cummins 6CT crankshaft options are available, each engineered to meet specific applications within the 8.3L platform.

Cummins 6CT Standard Crankshaft Assembly

The standard Cummins 6CT crankshaft is a forged steel component designed for maximum durability and long service life. This crankshaft is precision-machined, dynamically balanced, and ready for use in heavy-duty environments where the engine operates under continuous load.

Key Features:

• High-strength forged steel construction.

• Machined journals for exact bearing clearances.

• Balanced counterweights to minimize torsional vibration.

• Built to handle continuous-duty marine and industrial applications.

This crankshaft is an ideal replacement when rebuilding a 6CT engine that operates in traditional heavy-equipment, marine propulsion, or generator applications.

Cummins 6CT Crankshaft for Engines with CM850 Control Module

Some later versions of the Cummins 6CT incorporate electronic monitoring and control through the CM850 control module. These engines require a specific crankshaft design that integrates machining compatible with electronic timing sensors.

Key Benefits:

• Designed for seamless integration with CM850-equipped Cummins 6CT engines.

• Ensures accurate crankshaft position readings for engine control and timing.

• Retains Cummins durability while meeting updated electronic requirements.

• Provides long-term reliability under electronically monitored operation.

This crankshaft is best suited for Cummins 6CT applications that require electronic synchronization, ensuring the engine’s control module receives accurate feedback from the rotating assembly.

Crankshaft Bearings for Cummins 6CT

The bearings that support the crankshaft are just as critical as the crankshaft itself. The Cummins 6CT uses main bearings and connecting rod bearings in both standard and oversize options.

Standard Size Bearing Shells

• Designed for crankshafts within factory specification.

• Provide a smooth, durable surface for crankshaft journals.

• Maintain correct lubrication and clearance.

Oversize Bearings – 0.25 mm and 0.50 mm

When a crankshaft has been reground, oversize bearings restore correct clearances. Cummins 6CT oversize bearing sets are available in increments of 0.25 mm and 0.50 mm.

Benefits:

• Extends crankshaft service life after machining.

• Maintains correct oil film between bearing and crank journal.

• Prevents scoring, heat damage, and premature wear.

Crankshaft Seal Kits for Cummins 6CT

To prevent oil loss and maintain oil pressure, the Cummins 6CT crankshaft uses specialized front and rear seals.

Front Crankshaft Seal Kits

• Seal and sleeve included for a complete repair.

• Prevent oil leakage from the timing cover end.

• Designed to withstand high-heat and high-pressure conditions.

Rear Crankshaft Seal Kits

• Installed at the flywheel housing to prevent oil leaks.

• Available in variations for standard housings, dry clutch housings, and wet clutch housings.

• Double-lip options provide additional protection against leakage.

Replacing seals during a rebuild is essential to avoid costly downtime from oil loss or clutch contamination.

Vibration Dampers for Cummins 6CT

The vibration damper, also known as a harmonic balancer, is bolted to the crankshaft to absorb torsional vibrations. Without a properly functioning damper, the crankshaft may develop cracks or excessive wear.

Features of Cummins 6CT Vibration Dampers:

• Balanced to absorb rotational harmonics.

• Available in different outside diameters to fit specific applications.

• Extends crankshaft and bearing life.

Replacing the damper is recommended whenever the rubber isolator shows signs of hardening, cracking, or separation.

Expansion Plug Kits for Cummins 6CT

Expansion plugs, or freeze plugs, seal casting holes in the Cummins 6CT block. Over time, they may corrode, especially in marine environments. The Cummins 6CT expansion plug kit provides a full set of plugs to ensure a leak-free rebuild.

Maintenance Tips for the Cummins 6CT Crankshaft Assembly

• Perform oil changes regularly to protect bearing surfaces.

• Inspect seals for leaks at every major service.

• Monitor oil pressure for early signs of bearing wear.

• Replace vibration dampers during major overhauls.

• Check bearing clearances carefully during installation.

Why Choose Diesel Pro Power for Cummins 6CT Crankshaft Parts

• Proven Experience – Trusted by over 40,000 customers worldwide.

• Global Shipping – Parts delivered fast to anywhere in the world.

• Expert Support – Our team specializes in Cummins 6CT applications.

• High-Quality Standards – All parts meet or exceed Cummins specifications.