Product Description
Genuine Cummins
Cummins 3920922 — P7100 Injection Pump Lock Washer
MPN: 3920922 | Also Known As: pump gear lock washer | Location: Under the P7100 pump gear nut
Why This Part
- ✓ OE lock washer that secures the P7100 pump gear nut and helps maintain timing.
- ✓ Direct-fit for 1994–1998 Ram 5.9L 12-valve (P-pump).
- ✓ Correct thickness & hardness for reliable clamp load on the pump gear.
- ✓ Genuine Cummins quality for durability in high-vibration diesel use.
OE Fit Stock Replacement 1 Per Pump
Quick Specs
| Type | Lock washer (P7100 pump gear) |
|---|---|
| OE Part # | 3920922 |
| Position | Under injection pump gear nut (P7100) |
| Qty Required | 1 per pump (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1994–1998 | 5.9L 12-Valve Cummins (P7100) | Ram 2500/3500 |
Notes: For P-pump conversions or industrial 6B applications, verify by pump model/ESN before ordering.
Often Paired With
- Pump Gear Nut: Cummins 3920921 (mates with this lock washer)
- Front cover seal & hardware if servicing timing components
What’s In The Box
- (1) Genuine Cummins Lock Washer (3920922)
- Nut and other hardware sold separately
Install Tips
- Position washer under the pump gear nut; use a new nut where possible.
- Torque to factory spec and follow Cummins timing procedures.
- Re-check clamp load after any timing adjustment or gear service.
FAQ
WILL THIS FIT MY 1994–1998 12-VALVE CUMMINS RAM?Yes—this OE washer is for the P7100 injection pump gear on 1994–1998 Ram 2500/3500 5.9L 12-valve (verify by VIN/ESN).
WHERE DOES THE WASHER GO?It installs directly under the P7100 pump gear nut on the injection pump shaft.
HOW MANY DO I NEED?One per pump. We recommend replacing the gear nut (3920921) at the same time.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 3920922 with correct hardness and thickness for secure clamping.
DOES THIS FIT COMMON-RAIL 5.9/6.7 ENGINES?No—this part targets P7100 (mechanical) applications. Common-rail engines use different hardware.
