Enginetech BB157J.50 is a .50mm undersize connecting rod bearing set for 2002-2009 Chevy, GMC, Buick, Oldsmobile 4.2L 256ci I6 engines.
Important Notes:
- Sized for crankshaft rod journals machined .50mm undersize. Measure journal diameter before installation - installing on the wrong journal size will cause immediate clearance failure.
- Always replace rod bearings as a complete set. Never mix new bearings with used bearings - uneven wear and clearance differences will cause premature failure.
| Part Number | BB157J.50 |
| Bearing Size | .50mm Undersize |
| Quantity Per Set | 6 pairs (12 bearings) per set |
| Engine | 4.2L 256ci I6 |
| Year Range | 2002-2009 |
| Makes | Buick, Chevrolet, GMC, Isuzu, Oldsmobile, Saab |
| Country of Origin | IL |
| Weight | .5 lbs |
| UPC | 707473639507 |
| OEM Cross-Refs | MAHLE:CB-1882A |
Complete set covers all 6 connecting rod journals for the I6 application - one set required per engine.
Fitment:
- 2002-2004 Oldsmobile Bravada 4.2L 256ci I6
- 2002-2006 Chevrolet Trailblazer EXT 4.2L 256ci I6
- 2002-2006 GMC Envoy XL 4.2L 256ci I6
- 2002-2009 Chevrolet Trailblazer 4.2L 256ci I6
- 2002-2009 GMC Envoy 4.2L 256ci I6
- 2003-2008 Isuzu Ascender 4.2L 256ci I6
- 2004-2005 GMC Envoy XUV 4.2L 256ci I6
- 2004-2007 Buick Rainier 4.2L 256ci I6
- 2005-2009 Saab 9-7x 4.2L 256ci I6
Enginetech rod bearings are engineered to OEM specifications, drawing on over 40 years of engine rebuilding expertise to deliver the precise clearance, crush, and eccentricity required for long-term durability under both stock and moderate-performance loads. Each set is application-specific: materials, wall thickness, oil clearance, and surface finish are all matched to the connecting rod journal geometry and operating loads of the engine family it serves. Rod bearings are a wear component and must be selected to match the crankshaft journal size - bearings sized for standard journals will not seat correctly on undersize-machined journals and vice versa, so verify your journal measurement with a precision micrometer before ordering or installing. Always replace rod bearings as a complete set. Mixing new bearings with used bearings produces uneven oil clearance across cylinders and accelerates wear on the freshly installed bearings - the small cost of a complete set is insurance against premature failure on the bearings you just paid to install. Enginetech documents every set with clear application-specific notes, journal-size designation, and cross-references so the right part lands on the bench the first time.
WARNING: This product can expose you to chemicals including lead and nickel, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
