Crankshaft & Main Bearings
- Loosen crankshaft bearing caps in sequence shown. See Figure . Inspect journals for wear, taper and out-of-round condition. I f specifications are exceeded, grind journals to undersize or replace crankshaft. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS under ENGINE SPECIFICATIONS.
- Standard main bearings are available in 5 different sizes and are color-coded. Upper bearing half has an oil groove. Bearing No. 1 is at crankshaft pulley end of engine. Bearing No. 5 is at flywheel end of engine.
- Main bearing journal diameter is determined by numerical mark ("1", "2" or "3") stamped on crankshaft web No. 2. See Fig 1 . The numerical marks on crankshaft web No. 2, read left to right, indicate journal diameters of bearings No. 1, 2, 3, 4 and 5, respectively. See CRANKSHAFT MAIN BEARING JOURNAL DIAMETERS .
- Determine bearing cap bore diameter with bearing removed. Bearing cap bore diameter is determined by letter ("A", "B" or "C"). See Fig 2 . See appropriate MAIN BEARING CAP BORE DIAMETER .
- The letters stamped on cylinder block, read left to right, indicate cap bore diameters of bearing caps No. 1, 2, 3, 4 and 5, respectively. Five standard main bearing sizes are available. Bearing thickness is determined by color code. See COLOR CODE FOR STANDARD MAIN BEARINGS .
- Use numerical marks on crankshaft webs and letters stamped on cylinder block mating surface to determine correct replacement bearing. See STANDARD MAIN BEARING APPLICATIONS . Tighten crankshaft bearing caps to specification and in sequence shown. See Figure .
CRANKSHAFT MAIN BEARING JOURNAL DIAMETERS
| Numbers Stamped On Web No. 2 | In. (mm) |
|---|---|
| "1" | 2.2832-2.2835 (57.994-58.000) |
| "2" | 2.2830-2.2832 (57.988-57.994) |
| "3" | 2.2828-2.2830 (57.982-57.988) |
MAIN BEARING CAP BORE DIAMETERS
| Letters Stamped On Block | In. (mm) |
|---|---|
| "A" | 2.4409-2.4412 (62.000-62.006) |
| "B" | 2.4412-2.4414 (62.006-62.012) |
| "C" | 2.4414-2.4416 (62.012-62.018) |
COLOR CODE FOR STANDARD MAIN BEARINGS
| Color Painted | Thickness - In. (mm) |
|---|---|
| Green | .0785-.0786 (1.993-1.997) |
| Black | .0786-.0787 (1.997-2.000) |
| No Paint | .0787-.0788 (2.000-2.003) |
| Yellow | .0788-.0789 (2.003-2.006) |
| Blue | .0789-.0791 (2.006-2.009) |
STANDARD MAIN BEARING APPLICATIONS
| Letter Stamped On Block | Numbers Stamped On Crankshaft Webs | Color |
|---|---|---|
| "A" | "1" | Green |
| "A" | "2" | Black |
| "A" | "3" | No Paint |
| "B" | 1 | Black |
| "B" | "2" | No Paint |
| "B" | "3" | Yellow |
| "C" | 1 | No Paint |
| "C" | "2" | Yellow |
| "C" | "3" | Blue |