CUMMINS 4891178 OEM CONNECTING ROD WRIST PIN BUSHING – RAM 5.9L (1989–2007)

Product Description

The Cummins 4891178 OEM Connecting Rod Wrist Pin Bushing is the precision-machined small-end bushing used in the 5.9L Cummins connecting rod for both 12-Valve (1989–1998) and 24-Valve ISB engines (1998.5–2007). This genuine Cummins bushing ensures correct oil clearance, quiet wrist-pin movement, and long-term durability under high combustion loads. When completing a full rod reconditioning, engine overhaul, or performance refresh, using an OEM Cummins bushing guarantees factory-correct metallurgy and sizing.

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
• 2003–2007 Dodge Ram 2500/3500 – 5.9L 24-Valve ISB (Common Rail)
• 5.9L B-Series industrial/off-highway engines (verify by ESN)

This bushing must be pressed in and honed to size by a machine shop to match OEM wrist-pin clearance specifications.

Cummins-Only Cross-Reference

Related genuine Cummins internal engine components:
• Cummins 3900267 Tappet Cover Bolt Grommet Seal
• Cummins 3903924 Timing Pin – 12-Valve
• Cummins 3904409 Valve Stem Guide – 51.75mm

FAQ

Does the Cummins 4891178 wrist pin bushing fit all 5.9L engines?

Yes — it is used on all 1989–2007 5.9L Cummins connecting rods when rebuilt or reconditioned.

Does this bushing need to be honed after installation?

Yes. Wrist pin bushings must be sized/honed after pressing to achieve OE clearance and proper lubrication.

Can I install the wrist pin bushing at home?

Installation requires precision pressing and machine-shop honing. A professional rod reconditioning shop is recommended.

Is this bushing compatible with aftermarket forged pistons?

Yes — as long as the wrist-pin diameter matches OEM spec. Many performance builds still rely on OEM Cummins rod bushings.

Specifications for cummins 4891178