Re: 1997 Force 120 Outboard lower unit oil change
This is a copy and paste from the OEM service manual for Models 90/120 With Serial Numbers 0E093700 and Above.
Draining and Inspecting Gear
Housing Lubricant
WARNING
If gear housing is installed on engine, to avoid
accidental starting, disconnect (and isolate)
spark plug leads from spark plugs before working
near the propeller.
1. With gear housing in normal running position,
place a clean pan under housing and remove the
two vent screws and one fill/drain screw (with
gaskets).
2. Inspect gear lubricant for metal particles (lubricant
will have a ?metal flake? appearance). Presence
of fine metal particles (resembling powder)
on the drain plug bar magnet indicates normal
wear. The presence of metal chips on the drain
plug bar magnet indicates the need for gear housing
disassembly and component inspection.
3. Note color of gear lubricant. White or cream color
indicates presence of water in lubricant. Gear lubricant
which has been drained from a gear case
recently in operation will have a yellowish color
due to lubricant agitation/aeration. This is normal
and should not be confused with the presence of
water.
4. Presence of water in gear lubricant indicates the
need for disassembly and inspection of oil seals,
seal surfaces, O-rings, water pump gaskets as
well as gear housing components for damage.
Filling Gear Housing With
Lubricant
NOTE: Gear housing lubricant capacity is 22.5 fl. oz.
(665.2ml).
WARNING
If gear housing is installed on engine, to avoid
accidental starting, disconnect (and isolate)
spark plug leads from spark plugs before working
near the propeller.
Do not use automotive grease in the gear housing.
Use only Quicksilver Gear Lube or Quicksilver
Super-Duty Lower Unit Lubricant.
CAUTION
1. Remove any gasket material from ?Fill? and ?Vent?
screws and gear housing.
2. Install new gaskets on ?Fill? and ?Vent? screws.
IMPORTANT: Never apply lubricant to gear housing
without first removing ?Vent? screws or gear
housing cannot be filled because of trapped air.
Fill gear housing only when housing is in a vertical
position.
3. Remove lubricant ?Fill? screw and gasket from
gear housing.
4. Insert lubricant tube into ?Fill? hole, then remove
?Vent? screws and gaskets.
5. Fill gear housing with lubricant until excess starts
to flow out of one (first) ?Vent? screw hole.
6. Replace this lubricant ?Vent? screw and gasket
only and continue filling until excess starts to flow
out of second lubricant ?Vent? screw hole.
7. Replace second lubricant ?Vent? screw and gasket.
IMPORTANT: Do not lose more than one fluid
ounce (30cc) of gear lubricant while reinstalling
?FILL? screw.
8. Remove lubricant tube from ?Fill? hole; install ?Fill?
screw and gasket.[/CENTER]