Description
Sierra Metric Gear Lube Fill Adapter 18-99531 is a precision-engineered marine tool designed to facilitate lower unit gearcase oil changes by adapting standard imperial lube pump fittings to metric outboards.
Specifications & Compatibility
- Thread Sizes: It bridges an 8mm metric tip to a 3/8"-16 standard imperial thread, allowing common quart oil bottle pumps to connect securely to metric gearcases.
- Compatible Brands: Fits most 8mm metric applications including Honda, Nissan, Tohatsu, and Yamaha, as well as select Mercury and Evinrude outboards.
- Explicit Exclusions: It does not fit Suzuki outboards (which typically require a 10mm adapter like the Sierra 18-9795).
- Part Replacements: Directly replaces Mercury 91-883704Q03, 91-883704K03, and CDI 551-334M
