BLOCK 4428933 - Caterpillar

Machines Powered 3114, 3116, And 3126 Machine EnginesDescription of Change: The material for the main bearings in these machine engines has been changed from an aluminum alloy and steel back with a copper bond and lead/tin overlay to a bi-metal main bearing with an aluminum alloy and steel back. The new bi-metal main bearing is harder than the lead/tin overlay of the former main bearings. The increased hardness gives more consistent bearing clearance and greater wear resistance. The new bi-metal main bearing does have the ability to embed debris during start-up and conform to crankshaft geometry, similar to the properties of the former lead/tin overlay main bearings.Adaptable To: Oversize and undersize main bearings have not been changed to the new material. The sixth thrust bearing on the 3116 Machine Engine and 3126 Machine Engine has not been changed to the new bi-metal material, but will be changed when a bi-metal thrust bearing is developed. The bi-metal main bearings were introduced in 1995. The bi-metal main bearings became effective at first production for the 3126 Machine Engine. Each affected main bearing part number has been canceled, and replaced by a new part number. When ordering main bearings, use the parts book for your engine. The Numerical Parts Record (NPR) will then direct you to the correct part number.