Product Description
Cummins 4955857 OEM Main Bearing Set (.020 / 0.50MM) – 5.9L/6.7L (1989–2018)
The Cummins 4955857 OEM Main Bearing Set (.020 / 0.50MM) is a genuine Cummins replacement bearing set designed for 5.9L and 6.7L B-Series diesel engines requiring a 0.020-inch (0.50mm) undersize crankshaft bearing. Manufactured to Cummins' strict engineering standards, this bearing set provides the durability, oil control, and load-carrying capacity required for stock rebuilds, performance engine builds, and heavy-duty diesel applications.
Whether you're rebuilding a high-mileage engine or completing a precision-machined overhaul, the Cummins 4955857 main bearing set delivers the proper fit and reliability needed to maintain crankshaft support, oil pressure stability, and long engine life. Designed specifically for machined crankshafts measuring 0.020-inch undersize, this OEM bearing set helps restore factory tolerances and performance.
Features
- Genuine Cummins OEM main bearing set
- Designed for crankshafts machined 0.020 inch (0.50mm) undersize
- OEM-quality materials and construction
- Provides proper crankshaft support and oil clearance
- Helps maintain stable oil pressure and bearing lubrication
- Excellent for engine rebuilds and overhauls
- Designed for long service life in demanding diesel applications
- Manufactured to Cummins factory specifications
- Direct replacement for specified B-Series Cummins engines
- Ideal for stock, towing, and performance engine builds
Fitment
- 1989–2002 Cummins 5.9L 12-Valve Engines
- 1998.5–2002 Cummins 5.9L 24-Valve Engines
- 2003–2007 Cummins 5.9L Common Rail Engines
- 2007.5–2018 Cummins 6.7L Common Rail Engines
- Dodge Ram 2500 and 3500 equipped with Cummins diesel engines
- Industrial and commercial Cummins B-Series applications
- Engine rebuilds requiring 0.020 inch undersize main bearings
Note: This bearing set is intended for crankshafts that have been machined 0.020 inch (0.50mm) undersize. Always verify crankshaft journal measurements before ordering to ensure proper bearing clearance and fitment.
What's Included
- Cummins 4955857 OEM Main Bearing Set
- Upper and lower main bearing shells
- Complete engine main bearing set for specified application
Specifications
- Manufacturer: Cummins
- Part Number: 4955857
- Product Type: Main Bearing Set
- Bearing Size: 0.020 Inch Undersize
- Metric Size: 0.50mm Undersize
- Engine Compatibility: Cummins 5.9L and 6.7L B-Series
- Engine Years: 1989–2018
- Application: Engine Rebuild and Overhaul
- Material: OEM Cummins Bearing Material
- Position: Main Bearings
- Fitment Type: Direct Replacement
- Condition: New Genuine Cummins Part
Cross Reference Numbers
4955857, Cummins 4955857, 0.020 Main Bearing Set, 0.50MM Main Bearing Set, Cummins B-Series Main Bearings, Cummins 5.9L Main Bearing Set, Cummins 6.7L Main Bearing Set
FAQ
What does 0.020 inch undersize mean?
A 0.020 inch undersize bearing is designed for use with a crankshaft that has been machined 0.020 inch smaller than the original factory journal diameter during engine rebuilding.
Will this fit a standard-size crankshaft?
No. The Cummins 4955857 bearing set is specifically designed for crankshafts that have been machined 0.020 inch (0.50mm) undersize. Standard crankshafts require standard-size bearings.
Does this fit both 5.9L and 6.7L Cummins engines?
Yes. This bearing set is designed for applicable Cummins B-Series 5.9L and 6.7L diesel engines from 1989 through 2018.
Why should I use OEM Cummins bearings?
Genuine Cummins bearings are engineered to meet factory specifications for material quality, oil clearance, durability, and long-term reliability.
Is this a complete main bearing set?
Yes. The Cummins 4955857 includes the complete main bearing set required for engine assembly in the specified applications.
Should crankshaft measurements be verified before ordering?
Absolutely. Proper crankshaft journal measurements should always be confirmed during the rebuilding process to ensure the correct bearing size is selected.
