Cummins NT855 Engine Parts – Connecting Rod Section

The connecting rod assembly in a Cummins NT855 engine is one of the most important components in the entire power unit. Acting as the critical link between the piston and the crankshaft, connecting rods convert the linear motion of the piston into the rotational power that drives the engine. Over time, the constant high loads, heat, and stresses within the combustion chamber can lead to wear on rod bearings, bushings, and other related parts. Replacing these components with high-quality parts ensures the long-term reliability, fuel efficiency, and smooth operation of your NT855 engine.

Diesel Pro Power supplies connecting rod components for Cummins NT855 and NH855 Big Cam engines, trusted by over 40,000 satisfied customers worldwide. All components are precision-manufactured to OEM specifications, ensuring consistent performance in both marine and industrial applications.

Connecting Rod Bearings for Cummins NT855

Standard Size Connecting Rod Bearings

Standard rod bearings are designed for engines where the crankshaft journals have not been ground undersize. These bearings consist of an upper and lower half shell that together support one connecting rod on the crankshaft. Precision machining ensures correct oil clearance, allowing proper lubrication and preventing metal-to-metal contact.

• Fits Cummins NT855 and NH855 Big Cam engines

• Designed to service one connecting rod per set

• Manufactured for durability under heavy loads

• Maintains factory clearances for long engine life

These standard rod bearings are a direct replacement option during rebuilds or maintenance intervals.

Oversize Connecting Rod Bearings – 0.010"

When a crankshaft journal is worn or has been reground, oversize bearings are required to maintain proper oil clearance. The 0.010" oversize connecting rod bearings are built for Cummins NT855 and NH855 engines where a minimal amount of material has been removed from the crankshaft surface.

• Ensures tight fit and optimal lubrication after crankshaft machining

• Prevents premature bearing failure from improper clearance

• Sold as a complete set for one connecting rod

Oversize Connecting Rod Bearings – 0.020"

For engines where more significant wear has occurred, 0.020" oversize bearings are available. These are ideal for crankshafts that have been ground down further during overhaul to restore smooth surfaces.

• Designed for Cummins NH855 Big Cam and NT855 applications

• Provides correct bearing clearance even on reground crankshafts

• Manufactured to withstand high combustion pressures typical of heavy-duty diesel operation

With properly selected oversize bearings, you can restore crankshaft function and ensure extended service life for your engine.

Cummins NT855 Connecting Rod Bushings

Piston Pin Bushings

Located at the small end of the connecting rod, bushings support the piston pin, allowing it to rotate smoothly with minimal friction. Over time, these bushings can wear due to constant oscillating motion and high temperatures.

• Designed specifically for Cummins NT855 and NH855 engines

• Provides a precise fit for piston pin installation

• Reduces wear on connecting rods and pins

• Essential for smooth piston movement and proper combustion performance

Replacing worn piston pin bushings prevents knocking noises, uneven wear on pistons, and potential damage to the connecting rods themselves.

Why Proper Connecting Rod Maintenance Matters

The NT855 engine is known for its strength and durability, but like all diesel engines, it depends heavily on precision clearances and lubrication within its rotating assembly. Worn connecting rod bearings or bushings can lead to:

• Loss of oil pressure – Causing downstream failures in bearings, turbochargers, and valve components.

• Engine knocking – From excessive clearance between rod bearings and crankshaft journals.

• Piston scoring – Due to improper alignment or lubrication at the piston pin.

• Catastrophic failure – If a connecting rod breaks free from the crankshaft during operation.

Routine inspections, proper measurement of crankshaft journals, and timely replacement of bearings and bushings are critical for extending engine life.

Applications of Cummins NT855 Connecting Rod Components

The Cummins NT855 engine powers a wide variety of applications, including:

• Marine propulsion systems in commercial vessels, workboats, and tugs

• Standby and continuous-duty industrial generators

• Heavy equipment such as drilling rigs and mining machinery

• Locomotive and large construction machinery applications

Regardless of the application, connecting rod bearings and bushings play a vital role in keeping the NT855 running under heavy load conditions.

Diesel Pro Power Advantage

Choosing Diesel Pro Power for your Cummins NT855 connecting rod components means:

• Worldwide Shipping – Fast delivery to over 180 countries.

• Expert Support – Backed by a team specializing in Cummins heavy-duty diesel engines.

• Proven Reliability – Serving more than 40,000 satisfied customers.

• Comprehensive Catalog – Covering all major NT855 engine systems, from fuel and cooling to pistons, rods, and cylinder heads.