MAINTENANCE PRACTICES WITH REGARD TO ENGINE BEARINGS

One approach to the problem of the proper installation of engine bearings is to consider the following points individually (Figure 1).

1. 1.
   Is the housing (connecting rod or main bearing saddle) into which the bearing is being assembled round, reasonably smooth, straight, and of proper size?
2. 2.
   Is the new insert bearing to the correct physical requirements; that is, similar grooving and oil holes, proper materials, and correct undersize for the replacement?
3. 3.
   Is the shaft round, smooth and straight, and of correct size?
4. 4.
   Is the oil clearance correct?
5. 5.
   Will good clean oil be supplied to the bearings under pressure?

These are the major elements when confined to one engine bearing. Deviations from practical limits on any of these can lead to trouble, in the form of shortened bearing life or possible immediate failure, depending upon the degree of the deviation.

Obviously when more than one bearing in a direct line is involved, alignment of the two or more bearings becomes an additional consideration.