Mercury & Mariner 1999-2006 75, 90, 115 HP 4-Stroke Gearcase Parts Diagrams

Dive into OBParts' dedicated section for Mercury & Mariner 4-cylinder, 4-Stroke outboard lower unit components covering 75, 90, and 115 HP models built between 1999 and 2006. This page showcases an extensive range of crucial parts, including:

• Propeller shafts, shift shafts, and bearing kits
• Clear, detailed parts diagrams for accurate identification and assembly
• OEM-equivalent aftermarket quality from trusted brands like Red Rhino and EMP
• Seamless navigation through Mercury & Mariner parts categories—from powerheads and gaskets to gearcases and rebuild kits

Whether you're restoring, repairing, or rebuilding, you'll find all the essential components to rebuild your lower unit with confidence and precision.

We offer a complete rebuild kit for this gearcase as well as individual aftermarket parts. Please select from the following list or from the photos below:

Complete Rebuild Kit

The following parts correspond to the numbers on the diagram to the right:

1. Inner Forward Gear Bearing
2. Outer Forward Gear Bearing
3. Top Drive Shaft Bearing
4. Bottom Drive Shaft Bearing
5. Reverse Gear Thrust Bearing
6. Forward Carrier Gear Bearing
7. Aft Carrier Bearing
8. Cam Follower Kit
9. Gear Set
• 75-90 HP
• 115 HP
10. Clutch Dog
11. Clutch Dog Pin
12. Clutch Dog Spring
13. Prop Shaft
14. Bearing Carrier
15. Drive Shaft
16. Pinion Nut
17. Shim Kit

 We also offer the following items:

• Shift Cam
• Water Pump Kit
• Lower Seal Kit
• Bearing Kit