Product Description
Cummins 4932378 OEM Connecting Rod Bearing (.040 Undersize / 1.00 MM) – Ram 5.9L (1989-2002)
The Cummins 4932378 OEM Connecting Rod Bearing (.040 Undersize / 1.00 MM) is a genuine Cummins replacement connecting rod bearing designed for rebuilt or machined crankshaft applications on 1989-2002 Dodge Ram 5.9L Cummins engines. Manufactured to Cummins OE specifications, this bearing provides the proper oil clearance, load capacity, and durability required to restore engine reliability after crankshaft reconditioning. The 4932378 bearing is intended for crankshaft journals that have been ground .040 inch (1.00 mm) undersize during the engine rebuilding process.
Built with genuine Cummins materials and precision machining standards, the 4932378 connecting rod bearing helps maintain proper oil film strength and bearing support under heavy-duty towing, work, and performance conditions. This bearing is commonly used during complete engine overhauls and should always be matched to the correct journal size and corresponding bearing components.
Features
- Genuine Cummins OEM connecting rod bearing
- .040 inch undersize (1.00 mm) repair bearing
- Designed for reground crankshaft journals
- Manufactured to OE Cummins specifications
- Provides proper oil clearance and bearing support
- Maintains oil film strength under heavy load
- Ideal for engine rebuild and overhaul applications
- Precision-machined for durability and reliability
- Commonly used on 1989-2002 5.9L Cummins engines
- Direct replacement for worn or damaged rod bearings
Fitment
- 1989-1993 Dodge Ram 5.9L Cummins 12-Valve
- 1994-1998 Dodge Ram 5.9L Cummins 12-Valve
- 1998.5-2002 Dodge Ram 5.9L Cummins 24-Valve
- 5.9L Cummins B-Series Engines
- Applications utilizing machined connecting rods
- Engine rebuild and crankshaft repair applications
Note: This bearing is designed for crankshafts that have been machined .040 inch (1.00 mm) undersize. Verify crankshaft journal measurements, ESN, rod style, and bearing requirements before ordering. Matching lower bearing shells are required for complete installation.
What's Included
- (1) Genuine Cummins 4932378 Connecting Rod Bearing Shell
- Factory Cummins Packaging
Specifications
- Manufacturer: Cummins
- Part Number: 4932378
- Part Type: Connecting Rod Bearing
- Bearing Size: .040 Inch Undersize
- Metric Size: 1.00 MM Undersize
- Application: Reground Crankshaft Journals
- Engine Family: Cummins B-Series 5.9L
- Engine Years: 1989-2002
- Bearing Position: Upper Connecting Rod Bearing Shell
- Material: Genuine Cummins OE Construction
- Cross Reference: 3901174, 3901234
- Installation Requirement: Must Be Matched to Proper Lower Bearing
Cross Reference Numbers
4932378, 3901174, 3901234, BEARING CON ROD 040, CON ROD BEARING 1.00MM, CUM4932378
FAQ
What does .040 undersize mean?
A .040 undersize bearing is designed for a crankshaft journal that has been machined or ground .040 inch (1.00 mm) smaller than factory specifications during an engine rebuild.
Will this fit a stock, unmachined crankshaft?
No. This bearing is specifically designed for crankshafts that have been machined .040 inch undersize. Always measure the crankshaft journals before ordering.
Is this a genuine Cummins part?
Yes. The 4932378 is a genuine OEM Cummins connecting rod bearing manufactured to factory specifications.
How many bearings are required per engine?
A complete 5.9L Cummins engine requires six upper and six lower rod bearing shells. This listing is for an individual bearing shell and matching components must be purchased separately.
Will this fit all 1989-2002 Cummins engines?
It fits many 1989-2002 5.9L Cummins applications using machined connecting rods, but engine serial number verification is always recommended before ordering.
Should rod bearings be replaced during an engine rebuild?
Yes. Rod bearings are considered wear items and should be inspected and typically replaced whenever the crankshaft is removed, machined, or the engine is rebuilt.
