Product Description
The CUMMINS 3955121 OEM ROCKER LEVER HOUSING (ROCKER BOX) is designed for 2003–2005 5.9L Cummins ISB diesel engines. This genuine Cummins rocker housing provides proper support and alignment for the rocker lever assembly while maintaining factory fitment, durability, and valve train reliability.
Use this component when repairing damaged rocker housings, replacing worn valve train components, or rebuilding a 5.9L Cummins cylinder head assembly. Always verify fitment by engine serial number before ordering.
FEATURES
- Genuine Cummins OEM rocker lever housing
- Direct-fit replacement for applicable 5.9L Cummins engines
- Supports proper rocker lever alignment and operation
- Designed to meet factory Cummins specifications
- Helps maintain correct valve train geometry and reliability
- Ideal for engine repair, maintenance, or rebuild applications
FITMENT
- 2003–2005 Dodge Ram 2500 5.9L Cummins
- 2003–2005 Dodge Ram 3500 5.9L Cummins
- Select Cummins ISB 5.9L industrial and commercial applications
WHAT'S INCLUDED
- 1 Cummins 3955121 OEM Rocker Lever Housing (Rocker Box)
CROSS-REFERENCE AND RELATED PRODUCTS
- Cummins 3955121
- Cummins Rocker Lever Components
- Cummins Valve Bridge Components
- Cummins Pushrods and Valve Train Hardware
SPECIFICATIONS
- Manufacturer: Cummins
- Part Number: 3955121
- Part Type: Rocker Lever Housing / Rocker Box
- Engine Compatibility: 5.9L Cummins ISB
- Fitment Years: 2003–2005
- Vehicle Application: Dodge Ram 2500 / 3500
- Condition: New OEM Cummins
- Installation Type: Direct Replacement
- Valve Train Component: Yes
FAQ
Will this rocker lever housing fit my truck?
This part fits many 2003–2005 5.9L Cummins applications. Always verify fitment by engine serial number before ordering.
What is a rocker lever housing?
The rocker lever housing, often called a rocker box, supports the rocker lever assembly and helps maintain proper valve train alignment and operation.
Is this a genuine Cummins OEM part?
Yes. Cummins 3955121 is a genuine OEM rocker lever housing manufactured to Cummins factory specifications.
What is included with this listing?
This listing includes one Cummins 3955121 OEM rocker lever housing.
When should a rocker housing be replaced?
Replacement may be necessary if the housing is cracked, damaged, excessively worn, or being replaced during major cylinder head or valve train repairs.
Do I need any related parts?
Inspect rocker levers, valve bridges, pushrods, adjustment hardware, and other valve train components during installation and replace worn parts as needed.
