ACL Bearings 4M7189A-.25 Main Bearing Set 0.25mm Undersize

The ACL Bearings 4M7189A-.25 is a high-quality crankshaft main bearing set engineered for precise fitment on reground crankshafts. This set features a 0.25mm (0.010 inch) undersize specification, designed for crankshafts that have been machined to restore journal surfaces or correct dimensional tolerances.

Key Features:

• 0.25mm (0.010 inch) undersize for reground crankshaft journals
• Aluminum-based bearing material construction for superior durability
• Manufactured to exacting OEM tolerances for optimal performance
• Steel-backed design provides structural integrity under high loads
• Tri-metal construction combines strength with conformability
• Engineered for proper oil clearance and hydrodynamic lubrication

ACL Bearings are manufactured in Tasmania, Australia with over 70 years of precision engine bearing experience. These bearings replicate original equipment specifications and metallurgy, making them ideal for engine rebuilds requiring undersize bearings for machined crankshafts. The aluminum-based bearing material offers excellent wear resistance and load-carrying capacity while maintaining the conformability needed for reliable engine operation.