1667-9011G99 Mercury Grey 20" Long Shaft Gearbox | Genuine Used Part

🔧 Product Description

Genuine Mercury / Mariner 100HP / 115HP Grey 20-Inch Long-Shaft Gearcase - Part Number: 1667-9011G99

A genuine grey-finished 20-inch lower unit for selected Mercury and Mariner inline-four 100HP and 115HP two-stroke outboards. This gearcase uses the three-jaw reverse-clutch design. Depending on the exact engine and gear set, the 9011 housing family was supplied with 2.07:1 or 2.31:1 gearing, so the ratio must be established from the installed gear tooth count or donor-engine catalogue.

⚙️ Key Features

• Genuine Mercury / Mariner grey gearcase
• Correct part number 1667-9011G99
• 20-inch long-shaft configuration
• Three-jaw reverse clutch
• Standard propeller rotation

🚤 Compatibility

• Mercury / Mariner 100HP inline-four carburetted two-stroke
• Mercury / Mariner 115HP inline-four carburetted two-stroke
• Documented serial groups 0A722297-0D283221
• Documented serial groups 0D283222-0G760299
• International serial group 9793577-0P016999
• Approximate application era: late 1980s through late 1990s
• Gear ratio must match the original engine specification

🔌 Function

The complete lower unit transmits crankshaft power to the propeller, selects forward, neutral and reverse and pumps cooling water through the engine.

⚠️ Common Signs of Failure

• Clutch dogs are rounded
• Gearcase jumps out of forward or reverse
• Oil becomes milky
• Driveshaft or propeller-shaft bearings become noisy
• Housing is cracked or skeg is damaged
• Gear ratio does not match the engine

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 1667-9011G41 is an earlier related grey long-shaft assembly
• Later catalogue references direct some applications to 1667-9011J7
• Colour and gear-ratio suffixes must be matched to the original engine and must not be treated as cosmetic supersessions alone

OEM / Related Numbers

• 1667-9011G99
• 1667-9011G41
• 1667-9011J7 later related assembly
• Related 2.07:1 and 2.31:1 gear sets
• Related three-jaw clutch, bearing carrier, driveshaft and shift shaft

Aftermarket / Verified Equivalents

• Specialist remanufactured Mercury inline-four lower units
• SEI replacement lower units are functional alternatives for supported 100HP / 115HP Mercury applications when ratio, driveshaft and shift system match
• Sierra, GLM and Mallory seal, bearing, clutch and water-pump service parts are available separately

📦 Condition

• Genuine used part
• Removed from running engine where applicable
• In good working condition unless otherwise stated