Crankshaft & Main Bearings
- Ensure main bearing caps are numbered for location and arrow on cap points toward timing belt end of crankshaft.
- Cylinder block main bearing bore size is indicated by a letter "A", "B" or "C" stamped on cylinder block See Fig 1. Ensure main bearing bore is within specification. See MAIN BEARING BORE SPECIFICATIONS table.
- Crankshaft main bearing journal size is indicated by numerical size mark, located near crankshaft counterweight. See Fig 2. Ensure main bearing journal is within specification. See MAIN BEARING JOURNAL DIAMETER SPECIFICATIONS table.
- If main bearing journal and main bearing bore are within specification replace main bearings with original size grade (color code). If color code on original bearing cannot be obtained, use size mark letter on cylinder block and number on crankshaft to determine proper size main bearing to be used. See MAIN BEARING SELECTION (STANDARD BEARINGS) table. Standard bearing thickness is as listed. See BEARING THICKNESS SPECIFICATIONS table.
- Main bearings are available in .010" (.25 mm) undersize. Undersize bearings are coded with 2 color code marks. See Fig 3. Undersize bearings are available in 5 thickness variations. See BEARING THICKNESS SPECIFICATIONS table.
- If necessary, regrind main bearing journals to .010" (.25 mm) undersize with a finished diameter of 2.0367-2.0374" (51.732-51.750 mm). Using finished journal diameter and letter marked on cylinder block, determine color code undersize bearing to be used. See MAIN BEARING SELECTION (UNDERSIZE BEARINGS) table.
MAIN BEARING BORE SPECIFICATIONS
| Letter Stamped On Cylinder Block | Diameter In. (mm) |
|---|---|
| A | 2.2047-2.2050 (56.000-56.006) |
| B | 2.2050-2.2052 (56.006-56.012) |
| C | 2.2052-2.2054 (56.012-56.018) |
MAIN BEARING JOURNAL DIAMETER SPECIFICATIONS
| Number On Crankshaft Counterweight | Diameter In. (mm) |
|---|---|
| 1 | 2.0470-2.0472 (51.994-52.000) |
| 2 | 2.0468-2.0470 (51.988-51.994) |
| 3 | 2.0465-2.0468 (51.982-51.988) |
NOTE:
Main bearings contain a color code marked on the side of main bearing. Standard main bearings contain only one color code, and undersize main bearings contain 2 color codes. See Fig 3.
MAIN BEARING SELECTION (STANDARD BEARINGS)
| Cylinder Block Letter | Crankshaft Number | Bearing Color Code |
|---|---|---|
| A | 1 | Green |
| A | 2 | Black |
| A | 3 | No Color Code |
| B | 1 | Black |
| B | 2 | No Color Code |
| B | 3 | Yellow |
| C | 1 | No Color Code |
| C | 2 | Yellow |
| C | 3 | Blue |
BEARING THICKNESS SPECIFICATIONS
| Color Code | In. (mm) | |
|---|---|---|
| Standard Bearings | ||
| Green | .0786-.0787 (1.996-1.999) | |
| Black | .0787-.0788 (1.999-2.003) | |
| No Color Code | .0788-.0789 (2.002-2.006) | |
| Yellow | .0789-.0790 (2.005-2.009) | |
| Blue | .0790-.0791 (2.008-2.012) | |
| Undersize Bearings | ||
| Green & Red | .0835-.0836 (2.121-2.124) | |
| Black & Red | .0836-.0837 (2.124-2.127) | |
| Red Only | .0837-.0838 (2.127-2.131) | |
| Yellow & Red | .0838-.0839 (2.130-2.133) | |
| Blue & Red | .0839-.0841 (2.133-2.137) | |
MAIN BEARING SELECTION (UNDERSIZE BEARINGS)
| Finished Journal Diameter Cylinder Block: In (mm) | Cylinder Block Letter | Bearing Color Code |
|---|---|---|
| 2.0371-2.0374 (51.744-51.750) | A | Green & Red |
| 2.0371-2.0374 (51.744-51.750) | B | Black & Red |
| 2.0371-2.0374 (51.744-51.750) | C | Red Only |
| 2.0369-2.0371 (51.738-51.744) | A | Black & Red |
| 2.0369-2.0371 (51.738-51.744) | B | Red Only |
| 2.0369-2.0371 (51.738-51.744) | C | Yellow & Red |
| 2.0367-2.0369 (51.732-51.738) | A | Red Only |
| 2.0367-2.0369 (51.732-51.738) | B | Yellow & Red |
| 2.0367-2.0369 (51.732-51.738) | C | Blue & Red |