King Engine Bearings MB 551AM 1.5 AM-Series Main Bearing Set +1.50mm Oversize Toyota 3K 4K

The King Engine Bearings MB 551AM 1.5 is an AM-Series crankshaft main bearing set designed for the Toyota 3K and 4K engine families. This set is supplied in a +1.50mm oversize to accommodate reground crankshafts during engine rebuilds, restoring proper oil clearances and extending engine service life.

King's AM-Series bearings feature a bimetal construction with an aluminum alloy base material equivalent to SAE-783, making them well-suited for low to medium load street and marine engine applications. The full-groove upper bearing design ensures consistent oil supply around the crankshaft journal for reliable lubrication at all operating conditions.

Key Features:

• AM-Series bimetal construction — aluminum base material equivalent to SAE-783 for proven durability
• +1.50mm oversize — engineered for use with crankshafts reground 1.50mm undersize
• Full groove design — promotes consistent oil distribution to main bearing journals
• Superior embeddability — allows small particles to embed into the bearing surface, reducing crankshaft journal wear
• Bull's Eye Tolerance™ Technology — precision wall thickness consistency shell-to-shell for accurate fitment
• Lead-free material — environmentally responsible and safe to handle

King Engine Bearings has been a trusted name in the engine bearing industry since 1960, supplying precision bearings to the automotive, marine, aviation, and motorsport markets. The MB 551AM 1.5 is the correct oversize main bearing choice for a thorough rebuild of the Toyota 3K or 4K engine.