Changing Gear Case Lubricant; 3-1/4 In. (83Mm) Diameter Gear Case - Mercury 40 FourStroke Service Manual

MAINTENANCE

Changing Gear Case Lubricant

3-1/4 In. (83mm) Diameter Gear Case

When adding or changing gear case 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 gear case 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 gear case.
Examine the drained gear case lubricant for metal particles. A small amount of fine 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.
DRAINING GEAR CASE
1. Place outboard in a vertical operating position.
2. Place a drain pan below outboard.
3. Remove vent plugs and fill/drain plug. Drain lubricant.
a -
b -
CHECKING GEAR CASE LUBRICANT LEVEL AND REFILLING GEAR CASE
1. Place outboard in a vertical operating position. Remove vent plug (a).
2. Place lubricant tube (b) into the fill hole and add lubricant until it appears at the vent hole (c).
IMPORTANT: Replace sealing washers if damaged.
3. Stop adding lubricant. Install the vent plug and sealing washer (a) before removing the
lubricant tube.
4. Remove lubricant tube and reinstall cleaned fill/drain plug and sealing washer (d).
Page 1B-14
Fill/drain Plug
Vent Plug
Gear Case Lubricant Capacity
14.9 fl oz (440 ml)
c
b
b
a
a
d
90-857046R1 NOVEMBER 2001