Gearcase Lubricant - Mercury 300R HD CMS Mechanical Operation And Maintenance Manual

4. Inspect the strainer for debris, blockage, or accumulation of mineral
deposits. Flush the strainer with fresh water. Use a nylon bristle brush to
help remove debris, blockage, or mineral deposits. If the strainer cannot
be cleared of debris, blockage, mineral deposits, or if the strainer is
damaged, replace the strainer.
5. Install the strainer into the exhaust water spray inlet assembly.
6. Install the hose onto the assembly. Verify the hose is secure by pulling up
on the hose.

Gearcase Lubricant

GEARCASE LUBRICATION
When adding or changing gearcase lubricant, visually check for the presence of
water in the lubricant. If water is present, it may have settled to the bottom and
will drain out prior to the lubricant, or it may be mixed with the lubricant, giving it
a milky colored appearance. If water is noticed, have the gearcase checked by
your dealer. Water in the lubricant may result in premature bearing failure or, in
freezing temperatures, will turn to ice and damage the gearcase.
Examine the drained gearcase lubricant for metal particles. A small amount of
metal particles indicates normal gear wear. An excessive amount of metal
filings or larger particles (chips) may indicate abnormal gear wear and should
be checked by an authorized dealer.
300R HD REQUIRED GEARCASE LUBRICATION
Extreme Performance Gear Lube ‑ SAE 90
GEARCASE LUBRICANT CAPACITY
NOTE: Gearcase lubricant capacity is approximate.
Sport Master
137 mm (5.44 in.)
DRAINING AND FILLING THE GEARCASE
Draining Gearcase
1. Place the outboard in a vertical operating position.
2. Remove the propeller. Refer to Propeller Replacement.
3. Place a pan below the gear housing to capture the lubricant.
MAINTENANCE
Gearcase Lubricant Capacity
Right‑hand rotation
Left‑hand rotation
Right‑hand rotation
Left‑hand rotation
78
64631
620 mL (21.0 fl oz)
720 mL (24.4 fl oz)
680 mL (23.0 fl oz)
eng