Propeller Installation; Trim Tab Adjustment And Replacement - Mercury 40 Service Manual

11. Check shift operation.
a. Gear housing should not engage when pro-
peller shaft is turned clockwise when in for-
ward gear.
b. Propeller shaft will rotate freely in either direc-
tion when gearcase is in neutral.
c. Propeller shaft will not rotate in either direc-
tion when gearcase is in reverse.
IMPORTANT: If shift operation is not as de-
scribed, remove the gear housing and correct the
shift operation.

Propeller Installation

WARNING
Disconnect and isolate spark plug leads when
working near the propeller to prevent the out-
board from starting.
1. Apply one of the following Quicksilver products
on propeller shaft splines.
– Anti-Corrosion Grease
– 2-4-C Marine Lubricant
2. Install components.
c
a
d
94
b
Anti-Corrosion Grease (92-850735A1)
94
a - Thrust Hub; Flat Surface Towards Propeller
b - Propeller
c - Tab Washer; Bend Tabs Down Against Nut Flats
d - Locknut; Torque to 55 lb. ft. (75 N·m)
6B-34 - LOWER UNIT
Do not misinterpret propeller shaft movement for
propeller movement, propeller and propeller
shaft however may move fore-and-aft. However,
the propeller itself should not move fore-and-aft
on the propeller shaft.
3. Re-check propeller nut for tightness after first
use. Check for tightness periodically, especially
if a stainless propeller is used.
4. Install and adjust trim tab as follows.
Trim Tab Adjustment and
Replacement
IMPORTANT: The trim tab is made of a special
alloy to aid in protecting the drive shaft housing
and gear housing from galvanic corrosion (cor-
rosion and pitting of metal surfaces). Do not
paint or place protective coating on the trim tab,
or trim tab corrosion protection function will be
lost.
1. Replace trim tab if 50% (or more) corroded. Mark
location of old trim tab on anti-ventilation plate
before removal; install new trim tab in same loca-
tion.
2. The trim tab will offset (balance) some of the
"steering load" that is caused by "propeller
torque" at higher speeds. If at higher speeds the
boat turns more easily to the left, loosen bolt,
move the trim tab (trailing edge) to the left (when
viewed from behind); re-tighten bolt. Turn trim tab
(trailing edge) to the right if the boat turns more
easily to the right.
a
b
50551
a - Trim Tab
b - Anti-Ventilation Plate
c - Retaining Bolt and Washer; Torque Bolt to 22 lbs. ft.
(29.8 N·m)
CAUTION
c
50553
90-852572R1 JANUARY 1998