Product Description
Cummins 4955858 OEM Main Bearing Set (.030) for 5.9L & 6.7L Cummins Engines
The Cummins 4955858 OEM Main Bearing Set (.030) is a genuine Cummins replacement bearing kit engineered for 5.9L and 6.7L B-Series diesel engines. Designed to meet original equipment specifications, this oversized .030 main bearing set provides the precision fit, durability, and load-carrying capability required during complete engine rebuilds and performance engine restorations.
Manufactured to Cummins' strict quality standards, the 4955858 main bearing set delivers reliable crankshaft support, proper oil clearance, and long-lasting durability in demanding diesel applications. Whether rebuilding a high-mileage work truck, restoring a fleet vehicle, or assembling a performance diesel engine, genuine Cummins bearings help ensure maximum engine life and reliability.
Features
- Genuine Cummins OEM main bearing set
- .030 oversized bearing specification
- Precision-machined for proper oil clearance and crankshaft support
- Designed to meet Cummins factory specifications
- Provides excellent load-carrying capability and wear resistance
- Ideal for engine rebuilds and crankshaft machining applications
- Manufactured for long service life and durability
- Direct replacement for applicable Cummins B-Series engines
- Helps maintain proper oil pressure and engine reliability
- Trusted OEM quality for street, towing, commercial, and performance applications
Fitment
- 1989–2002 Dodge Ram 5.9L Cummins 12-Valve
- 1998.5–2002 Dodge Ram 5.9L Cummins 24-Valve
- 2003–2007 Dodge Ram 5.9L Cummins Common Rail
- 2007.5–2018 Ram 6.7L Cummins
- Industrial and commercial Cummins B-Series applications
- Engine rebuilds requiring .030 oversized main bearings
Note: This is a .030 oversized main bearing set intended for engines that have undergone crankshaft machining. Always verify crankshaft dimensions and bearing clearance specifications before installation.
What's Included
- Cummins 4955858 OEM Main Bearing Set (.030)
- Upper and lower main bearing shells
- Complete set for applicable engine rebuild applications
Specifications
- Manufacturer: Cummins
- Part Number: 4955858
- Product Type: Main Bearing Set
- Bearing Size: .030 Oversized
- Engine Platform: Cummins B-Series
- Engine Compatibility: 5.9L and 6.7L Cummins
- Fitment Years: 1989–2018
- Application: Engine Rebuild and Restoration
- OEM Replacement: Yes
- Material: OEM Cummins Bearing Construction
- Installation Location: Crankshaft Main Journals
Cross Reference Numbers
4955858, Cummins 4955858, 4955858 OEM Main Bearing Set, Cummins Main Bearings .030, B-Series Main Bearing Set, 5.9 Cummins Main Bearings, 6.7 Cummins Main Bearings
FAQ
What does .030 oversized mean?
A .030 oversized bearing set is designed for use with a crankshaft that has been machined .030 inch undersize during an engine rebuild. Proper crankshaft measurements should always be verified before ordering.
Will this fit both 5.9L and 6.7L Cummins engines?
Yes. The Cummins 4955858 main bearing set is designed for applicable 5.9L and 6.7L B-Series Cummins diesel engines. Always verify engine serial number and machining specifications before installation.
Is this a genuine Cummins part?
Yes. The 4955858 is a genuine OEM Cummins replacement component manufactured to factory specifications.
When should oversized bearings be used?
Oversized bearings are typically required when the crankshaft has been machined during an engine rebuild. The correct bearing size depends on the final crankshaft journal dimensions.
Can I use these bearings in a performance engine build?
Yes. Genuine Cummins bearings are commonly used in stock rebuilds, towing applications, commercial engines, and performance diesel builds where OEM reliability is desired.
Should I plastigage the bearings during assembly?
Yes. Checking bearing clearance during engine assembly is recommended to ensure proper oil clearance and long-term engine reliability.
