CUMMINS 3920921 OEM P7100 INJECTION PUMP GEAR NUT – 5.9L 12-VALVE (1994–1998)

Product Description

The Cummins 3920921 OEM P7100 Injection Pump Gear Nut is the factory-correct retaining nut used to secure the gear on the P7100 (P-pump) injection pump found on 1994–1998 5.9L 12-Valve Cummins engines. This hardened OEM nut maintains proper clamp load on the pump shaft, ensuring stable timing, reliable pump operation, and long-term durability under high torsional loads. Using a genuine Cummins nut prevents backing-off, stripped threads, and timing drift common with inferior aftermarket hardware.

Whether you’re replacing a worn pump nut, performing pump timing adjustments, or rebuilding a P7100, the 3920921 gear nut is the only hardware approved by Cummins for proper retention of the injection pump gear.

Fitment

• 1994–1998 Dodge Ram 2500/3500 with 5.9L 12-Valve Cummins (P7100 injection pump)
• 5.9L 6BT engines equipped with Bosch P7100 pump

Note: Always torque to Cummins specifications and verify gear seating before final tightening.

Cross-Reference (Cummins-Only)

Related Cummins fuel-system and timing hardware:
• Cummins 3903924 OEM Timing Pin – 5.9L 12-Valve
• Cummins 3900267 OEM Tappet Cover Bolt Grommet Seal
• Cummins 3904408 OEM Valve Stem Guide – 60.50mm

FAQ

Is this the correct nut for the P7100 injection pump gear?

Yes. The 3920921 nut is the OEM Cummins gear-retention nut for the P7100 pump on 1994–1998 12-Valve engines.

Should this nut be replaced when timing the P7100?

Yes. Cummins recommends replacing high-load fasteners when loosened or removed. This ensures proper clamp load and prevents pump-gear slip.

What happens if the pump gear nut is not torqued correctly?

An improperly torqued nut can cause timing drift, hard starts, power loss, or pump damage. Always follow Cummins torque specifications.

Does this nut fit VE or VP44 pumps?

No. This nut is specific to P7100 (P-pump) applications only.

Specifications for cummins 3920921