What is the difference between standard size and undersize bearings?

Standard size bearings are meant for engines where the crankshaft and block surfaces are still within factory specifications. Undersize bearings are used when the crankshaft has been machined (ground down) to correct for wear or damage, requiring a slightly smaller bearing to maintain proper clearance.

What is the proper installation procedure for these main bearings?

Always refer to the manufacturer's official service manual for the correct installation procedure. This typically involves ensuring all surfaces are clean, applying assembly lube to the bearings and crankshaft journals, and torquing the main caps to the specified values in the correct sequence.

Are these bearings sold individually or as a set?

This product is a main bearing set, which includes all the necessary bearings to replace the main bearings for the entire engine as specified for your vehicle's B58B30 or S58B30 engine.

ACL BMW B58B30/S58B30 3.0L Inline 6 Standard Size Main Bearings

Specifications

Brand: ACL
Part #: 7M1512H-STD
UPC: 9315726470084

ACL BMW B58B30/S58B30 3.0L Inline 6 Standard Size Main Bearings

Name: ACL BMW B58B30/S58B30 3.0L Inline 6 Standard Size Main Bearings
Brand: ACL
Price: 267.93 USD
Availability: InStock

$267.93

On Backorder — Expected to ship by Mar 29, 2026

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

ACL BMW B58B30/S58B30 3.0L Inline 6 Standard Size Main Bearings. Fits 2016-2018 BMW 340i, 2018-2019 X3, and 2020 Toyota GR Supra. Essential for engine rebuilds.

Key Features

Fits 2016-2018 BMW 340i, 2018-2019 BMW X3, and 2020 Toyota GR Supra.
Standard size main bearings for B58B30 and S58B30 3.0L inline-6 engines.
Designed to meet original equipment specifications for reliable performance.
Well-built by ACL, a reputable manufacturer of engine components.
Essential for engine rebuilds and repairs where crankshaft support is needed.

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Fits these vehicles

BMW 340i 2016-2018
BMW X3 2018-2019
Toyota GR Supra 2020

Product Details

When rebuilding or repairing the engine in your BMW 340i, X3, or Toyota GR Supra, the main bearings are critical components. These ACL main bearings are built to the original equipment specifications for the B58B30 and S58B30 3.0L inline-6 engines found in these vehicles. They are essential for ensuring the crankshaft spins smoothly within the engine block, reducing friction and wear.

This set includes standard size main bearings, meaning they are designed to fit a crankshaft and block that are still within their original factory tolerances. ACL is known for producing well-built engine components, and these bearings are no exception. They are made with materials and manufacturing processes that aim to provide reliable performance and longevity for your engine rebuild. Proper installation of these bearings is key to a successful engine repair, so be sure to follow the manufacturer's service manual for torque specifications and lubrication procedures.

If you're undertaking a significant engine project, using quality replacement parts like these ACL main bearings is a smart choice. They are designed to fit right and perform as expected, helping you get your vehicle back on the road with confidence.