The diagram to the right is for a Mercruiser Alpha I Gen I Sterndrive Upper Drive for models from 1984-1990. The following parts correspond to the numbers on this diagram:

1. Bearing Kit
2. Lower Roller Bearing
• 1.50 Ratio
• 1.65, 1.84, 1.98 Ratios
3. Upper Roller Bearing
• Small (Type I) (Race OD 1.780)
• Large (Type II) (Race OD 1.938)
4. Upper Gear Set
• 1.50:1 Ratio (20:22 Teeth)
• 1.65:1 Ratio (24:24 Teeth)
• 1.84:1 Ratio (17:19 Teeth)
• 1.98:1 Ratio (20:24 Teeth)
5. Vent Screw & Gasket
6. Upper Bearing Shim Kit
7. Drive Shaft
8. Upper Retainer
9. U-Joint
10. Long Input Yoke
11. Drive Shaft Yoke
12. Center Socket

We also offer the following item:

• Upper Seal Kit