GEAR ASSEM. (57 Teeth) 9M2575 - Caterpillar

Fretting in main bearing and cap.First, use only a pencil grinder to remove the fretting material from the surfaces. When fretting material is removed from a main or connecting rod bearing bore, make sure all of the material is removed. It is better to remove a very small amount of the component surface than to have some fretting material left on the surface. Even a very small amount of fretting material left on a surface can decrease the oil film between the bearing and surface, which can cause damage to the new bearing.
Clean the area with a brush, soap and water to remove all debris.
After a pencil grinder has been used to remove the fretting material, use a 1P3537 Dial Bore Gauge to measure the bearing bore to make sure it is in specifications. This must be done with the caps installed and the cap bolts tightened to the correct torque.
If the bearing bores or rod bores are not in specifications, they must be reconditioned. It some times will be necessary to install a new connecting rod and cap.
During assembly, make sure the cap bolts are tightened to the correct torque.