Repair consists of replacement of defective parts.
Before installation, check the bearing sizes (FIG. 4-54 and 4-55). Main bearings
are two widths; the narrow bearings fit locations 1 and 9. The upper bearings
contain an oil hole, the lower bearings do not. Both are marked on the back to
Be sure the crankshaft, main bearing shells, thrust bearing retainer, and blockmain bearing bore are
clean. Use a lint-free cloth to clean as necessary.
Prevent dirt from mixing with the lubricant. Dirty lubricant causes equipment failure.
Place the new upper main bearing shells (sleeves) (1, FIG. 4-56) in the block (2). Align the tang in
the bearing with the slot in the block. The ends of the bearing shell (1) must be flush with the parting
face of the block (2).
FIGURE 4-56. Main Bearing Shell (Sleeve) Installation.