Enginetech BB2131.25 is a .25mm undersize connecting rod bearing set for 2014-2021 Mazda 2.5L 152ci I4 engines.
Important Notes:
- Sized for crankshaft rod journals machined .25mm 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 | BB2131.25 |
| Bearing Size | .25mm Undersize |
| Quantity Per Set | 4 pairs (8 bearings) per set |
| Engine | 2.5L 152ci I4 |
| Year Range | 2014-2021 |
| Makes | Mazda |
| Country of Origin | TW |
| Weight | .75 lbs |
| UPC | 707473449915 |
| OEM Cross-Refs | Topline:RBMA31 |
Complete set covers all 4 connecting rod journals for the I4 application - one set required per engine.
Fitment:
- 2014-2015 Mazda 6 2.5L 152ci I4
- 2014-2016 Mazda CX-5 2.5L 152ci I4
- 2014-2017 Mazda 5 2.5L 152ci I4
- 2014-2019 Mazda 3 2.5L 152ci I4
- 2014-2020 Mazda 3 Sport 2.5L 152ci I4
- 2014-2020 Mazda 6 2.5L 152ci I4
- 2016-2020 Mazda CX-9 2.5L 152ci I4
- 2017-2018 Mazda CX-5 2.5L 152ci I4
- 2019-2020 Mazda CX-5 2.5L 152ci I4
- 2020-2020 Mazda CX-30 2.5L 152ci I4
- 2020-2021 Mazda 3 2.5L 152ci I4
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 likely lead/nickel ?Çö verify, which is known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
