Main Bearing Grade Chart
- Make
- Aston Martin
- Model
- DB9 Factory Workshop Manual
- Year
- Issue 2, 2005
- Section
- Power Conversion › Main Bearing Grade Chart
03 EngineMain Bearing Grade Chart
Main Bearing Grade Chart
The finished diameter of the crankshaft main bearing bores is indicated by letters stamped on the cylinder block face. The first letter, e.g. ‘D’, refers to No.1 journal, the second letter element refers to No.2 journal and so on.
The finished diameter of the seven crankshaft main bearing journals are indicated by seven letters stamped in bearing number sequence on No.1 counterweight.
The first letter in the sequence refers to No.1 journal, the second letter refers to No.2 journal and so on.
- Read the first letter on the cylinder block face and note it.
- Read the first letter on No. 1 crankshaft counterweight and note it.
- Using the letters, select the correct bearing grade for No. 1 journal.
- Repeat steps 1-3 to obtain the correct bearing grades for journals 2-7.
Piston Skirt Grading Chart
| Grade | Piston Diameter ‘A1’Prior to Skirt | Cylinder Bore Diameter | |
|---|---|---|---|
| Coating | |||
| 1 | 88.970 / 88.980 | 89.000 / 89.010 | |
| 2 | 88.978 / 88.992 | 89.008 / 89.022 | |
| 3 | 88.990 / 89.000 | 89.020 / 89.030 | |
Skirt Coating adds 0.020 - 0.030 to the diameter as follows:
| Grade | Piston Diameter (Coated) | Clearance with Coating | |
|---|---|---|---|
| 1 | 88.990 / 89.010 | New Build -0.014 (interference) | |
| 2 | 88.998 / 89.022 | New Build + 0.024 (clearance) | |
| 3 | 89.010 / 89.030 | Service Limit + 0.050 (clearance) | |
| Torque Figures | Nm. | lb./ft. | |
|---|---|---|---|
| Description | |||
| Engine block spread tool | 25 | 18.5 | |
| Main bearings | 1. Bolts 1 to 14. | 37-43 | 27.5-32 |
| 2. Bolts 15 to 28. | 22-28 | 16.5-21 | |
| 3. Bolts 1 to 28. | 85°-95° | ||
| Main cap side bolts | 1. Bolts 29 to 42. | 22-28 | 16.5-21 |
| 2. Bolts 29 to 42. | 85°-95° | ||
| Connecting rods | 1. | 20-25 | 15-18.5 |
| 2. | 40-45 | 30-33.5 | |
| 3. | 105°-120° | ||
| Windage tray | 1. | 5-7 | 4-5.5 |
| 2. | 45° | ||
| Sump | 1. | 15 | 11.5 |
| 2. | 90° | ||
| Flywheel | 75-81 | 55.5-60 | |
| Damper plate (Auto only) | 30 | 22.5 | |
Parts & tools for this job For 2005 Aston Martin DB9
- PARTEngine gasket setSearch: Aston Martin DB9 2005 engine gasket set
- TOOLTorque wrenchSearch: 3/8 inch torque wrench
- TOOLFeeler gauge setSearch: feeler gauge set
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