Types of wear of main and connecting rod bearings
Examination
Main and connecting rod bearings must be replaced during a major engine overhaul, but previously used bearings should be carefully checked to restore the general condition of the engine to the time of repair.
The causes of crankshaft bearing failure are insufficient lubrication due to improper assembly, contamination and penetration of foreign particles, frequent engine overloads, corrosion, etc. Regardless of the cause of bearing failure, it should be eliminated.
Selection of main bearings
If bearings of standard size groups are installed, then the new bearing is selected according to the numbers applied to the one being replaced, as well as according to the numbers on the cylinder block and crankshaft.
Locations of standard main bearing size groups on 4-cylinder engines
The number on the block must match the number on the bearing.
Determining the bearing number on V6 3.0L engines
1. Labels 1, 2 and 3
2. Reference mark
3. Labels 0, 1 or 2
The liner number is determined from the table based on the journal numbers on the block and the number on the crankshaft.
| Number on the cylinder block | 1 | 2 | 1 | 3 | 2 | 1 | 3 | 2 | 3 |
| Number on the crankshaft | 0 | 0 | 1 | 0 | 1 | 2 | 1 | 2 | 2 |
| Insert number | 1 | 2 | 2 | 3 | 3 | 3 | 4 | 4 | 5 |
Determining the bearing number on 3.4L V6 engines
1. Labels 1, 2 and 3
2. Reference mark
3. Labels 0, 1 or 2
The liner number is determined from the table based on the journal numbers on the block and the number on the crankshaft.
| Number on the cylinder block | 1 | 2 | 3 | ||||||
| Number on the crankshaft | 0 | 1 | 2 | 0 | 1 | 2 | 0 | 1 | 2 |
| Insert number | 1 | 2 | 3 | 3 | 3 | 4 | 2 | 4 | 5 |
Selection of connecting rod bearings
If bearings of standard size groups are installed, then the new bearing is selected according to the numbers applied to the one being replaced and to the connecting rod cover.
After selection, measure the clearance in the journals (see subsection 3.3.9.3, subsection 3.3.12.2).