Product Description
Cummins 4891178 OEM Connecting Rod Wrist Pin Bushing – Ram 5.9L (1989–2007)
The Cummins 4891178 OEM Connecting Rod Wrist Pin Bushing is a genuine Cummins replacement bushing designed for the small-end of the connecting rod in 1989–2007 5.9L Cummins diesel engines. Precision-machined to OEM specifications, this wrist pin bushing provides proper piston pin support, correct oil clearance, reduced friction, and long-term durability in both stock and performance engine builds. It is commonly replaced during engine overhauls, connecting rod reconditioning, and complete rebuilds.
Using a genuine Cummins wrist pin bushing helps ensure proper piston movement, reduced wear, and factory-correct fitment. Whether you are rebuilding a 12-Valve 6BT, 24-Valve ISB, or Common Rail 5.9L Cummins engine, the 4891178 provides the quality and reliability required for long engine life.
Features
- Genuine Cummins OEM replacement component
- Precision-machined connecting rod wrist pin bushing
- Maintains proper piston pin clearance
- Reduces friction and connecting rod wear
- Designed for connecting rod reconditioning and engine rebuilds
- Factory-correct metallurgy and dimensions
- Suitable for stock and performance engine builds
- One bushing required per cylinder (six required per engine)
- Built for long service life and durability
- Direct replacement for worn or damaged wrist pin bushings
Fitment
- 1989–1998 Dodge Ram 2500/3500 5.9L 12-Valve Cummins (6BT)
- 1998.5–2002 Dodge Ram 2500/3500 5.9L 24-Valve ISB Cummins
- 2003–2007 Dodge Ram 2500/3500 5.9L Common Rail Cummins
- 5.9L Cummins B-Series industrial applications (verify by ESN)
- Engine rebuilds and connecting rod reconditioning projects
Note: Wrist pin bushings must be pressed into the connecting rod and properly honed to achieve OEM wrist pin clearance specifications. Professional machine shop installation is recommended.
What's Included
- One (1) Genuine Cummins 4891178 Wrist Pin Bushing
Specifications
- Manufacturer: Cummins Genuine Parts
- Part Number: 4891178
- Component Type: Connecting Rod Wrist Pin Bushing
- Alternative Name: Piston Pin Bushing
- Installation Location: Connecting Rod Small End
- Material: OEM-Specification Bearing Material
- Quantity Required: One Per Cylinder (Six Per Engine)
- Fitment: 1989–2007 Ram 5.9L Cummins
- Application: Engine Rebuilds and Rod Reconditioning
- Installation Requirement: Press Fit and Hone to Final Size
- Cooling System Compatibility: All 5.9L Cummins Configurations
- Engine Families: 6BT, ISB, Common Rail
Cross Reference Numbers
4891178, 3901085, 3941476
FAQ
Does the Cummins 4891178 fit all 5.9L Cummins engines?
Yes. The 4891178 wrist pin bushing is used in 1989–2007 5.9L Cummins engines, including 12-Valve, 24-Valve, and Common Rail applications. Always verify fitment by engine serial number when possible.
How many bushings do I need for a complete engine rebuild?
Each connecting rod requires one wrist pin bushing. A complete six-cylinder 5.9L Cummins engine requires six bushings.
Do wrist pin bushings need to be honed after installation?
Yes. The bushing must be pressed into the connecting rod and honed to the proper wrist pin clearance specification before final assembly.
Can I install this bushing myself?
Installation requires specialized equipment for pressing and precision honing. Most engine builders use a qualified machine shop to complete the installation.
Is this a genuine Cummins part?
Yes. Part number 4891178 is an OEM Cummins wrist pin bushing designed to meet factory specifications for fit, durability, and performance.
Can this be used in performance engine builds?
Yes. Many high-performance and competition engine builds continue to use genuine Cummins wrist pin bushings when rebuilding or reconditioning factory connecting rods.
