Product Description
The Cummins 3937438 OEM Rocker Lever Adjusting Screw is the correct factory-engineered valve lash adjuster used on 1989–1998 Dodge Ram trucks equipped with the legendary 5.9L 12-valve Cummins engine. Designed to restore precise valve lash settings, this OEM adjuster screw ensures quiet operation, reduced valvetrain wear, and long-term reliability. Unlike offshore alternatives, genuine Cummins hardware is manufactured to exact tolerances for perfect fit and consistent torque retention.
FITMENT
- 1989–1998 Dodge Ram 2500/3500 with 5.9L 12-Valve Cummins
- Applies to cylinders 1–6 (individual rocker lever adjuster screw)
CROSS-REFERENCE / RELATED CUMMINS PARTS
- Cummins 3910739 Rocker Lever Assembly – 5.9L 12V
- Cummins 3904374 Rocker Lever Pivot – 5.9L 12V
- Cummins 3900406 Pushrod – 5.9L 12V
FAQ
What does the rocker lever adjusting screw do?
It sets and maintains proper valve lash clearance. Incorrect lash can cause poor performance, noise, and premature valvetrain wear.
Is this part truly OEM?
Yes, this is a 100% genuine Cummins replacement part sourced through official channels.
How many adjusting screws are required?
Your 5.9L 12V engine uses one per rocker lever—a total of six screws if replacing the full set.
Do I need to adjust valve lash after installation?
Yes, Cummins specifies lash adjustment after installation and again after initial warm-up.
Can this be used with aftermarket rocker arms?
Yes, as long as the rocker arms are designed to accept OEM-spec threads and geometry.
Specifications for cummins 3937438
| Field | Value |
|---|---|
| Brand | Cummins Genuine Parts |
| Part Number | 3937438 |
| GTIN | Not Listed |
| UPC | Not Listed |
| Cross Reference | Used with rocker assemblies such as 3910739 |
| E-Codes | Not Applicable |
| Shipping Info | Ships via USPS or UPS; small-parcel |
| Prop 65 | No warning required |
