Adapter Gear Lube Fill Metric | Sierra 18-99531
Adapter Gear Lube Fill Metric | Sierra 18-99531
Metric gearcase lube fill adapter designed for 8mm applications across Honda, Nissan, Tohatsu, Yamaha, and select Mercury and Evinrude outboards. Features 8mm x 3/8-16 threading for secure, leak-free lubricant filling. Direct replacement for Mercury 91-883704Q03, 91-883704K03, and 551-33M, plus CDI equivalents. Not compatible with Suzuki models. Essential maintenance tool for keeping your outboard gearcase properly lubricated and protected.
- 8mm tip fits most Honda, Nissan, Tohatsu, Yamaha, some Mercury & some Evinrudes
- Does not fit Suzuki
- 8mm x 3/8-16
- Replaces Mercury 91-883704Q03, 91-883704K03, 551-33M
- Replaces CDI
