Product Description
Cummins 4955853 — Main Bearing Set, Standard Size (6B/ISB/QSB)
MPN: 4955853 | Also Known As: main bearings (STD), crankshaft main bearing set | Cross-Refs: 3802070, 3800290 (and others)
Why This Part
- ✓ OE metallurgy & geometry for proper oil clearances and quiet operation.
- ✓ Standard size (STD) bearings for unground crankshafts (undersizes available separately).
- ✓ Direct-fit across 5.9L & 6.7L ISB platforms when STD size is specified.
- ✓ Restores oil pressure & crank support after wear or rebuild.
Quick Specs
| Type | Main bearing set (crankshaft) |
|---|---|
| OE Part # | 4955853 (STD size) |
| Engine Families | 6B / ISB / QSB 5.9L & 6.7L |
| Set Contents | Main bearing shells; thrust bearing supplied per OE set configuration |
Important: Always measure the crank and verify size by ESN. If the crank has been ground, use the correct undersize bearings.
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–2002 | Ram 5.9L Cummins (12V & 24V VP44) | D/W & Ram 2500/3500 |
| 2003–2007 | Ram 5.9L ISB (24V Common-Rail) | Ram 2500/3500 |
| 2007.5–2018 | Ram 6.7L ISB (24V Common-Rail) | Ram 2500/3500 |
Industrial/Off-Highway: 6B/ISB/QSB 5.9 & 6.7 applications—verify by ESN and bearing size.
Often Paired With
- Rod Bearing Set (size-matched)
- Lower Engine Gasket Set (year-specific)
- Main bolts or studs (replace if stretched)
- Assembly lube & plastigage for clearance checks
What’s In The Box
- (1) Genuine Cummins Main Bearing Set, Standard Size (4955853)
- Related gaskets/fasteners sold separately.
Install Tips
- Inspect crank journals; polish or grind as required. Measure clearances and confirm size.
- Cleanliness is critical—keep caps and saddles free of debris.
- Apply assembly lube, torque caps to spec, and verify endplay.
- Follow Cummins service manual procedures for your ESN.
FAQ
WILL THIS FIT MY 1989–2018 5.9L/6.7L CUMMINS?Yes—this set covers 6B/ISB/QSB 5.9 & 6.7 applications. Always verify standard (STD) size by measurement/ESN.
IS THIS THE STANDARD (STD) SIZE?Yes—4955853 is the OEM standard size main bearing set. Undersizes are available separately if the crank has been ground.
DOES THIS SET INCLUDE THRUST BEARINGS?It’s supplied as an OE main bearing set; thrust bearing is included per Cummins set configuration. Verify contents by ESN if needed.
CAN I MIX STANDARD AND UNDERSIZE BEARINGS?No—use a matched set sized to the crank. Mixing sizes risks oiling issues and rapid wear.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 4955853 for proper fit, clearances, and durability.
