Mariner Mercury 105/140 JET, Service Manual

Page: 662 / 797

6D-10 - LOWER UNIT 90-824052R3 JUNE 2002
General Service
Recommendations
There may be more than one way to “disassemble”
or “reassemble” a particular part(s), therefore, it is
recommended that the entire procedure be read prior
to repair.
IMPORTANT: Read the following before
attempting any repairs.
In many cases, disassembly of a sub-assembly may
not be necessary until cleaning and inspection
reveals that disassembly is required for replacement
of one or more components.
Service procedure order in this section is a normal
disassembly-reassembly sequence. It is suggested
that the sequence be followed without deviation to
assure proper repairs. When performing partial
repairs, follow the instructions to the point where the
desired component can be replaced, then proceed to
“reassembly and installation” of that component in
the reassembly part of this section. Use the “Table of
Contents” (on back of section divider) to find correct
page number.
Threaded parts are right hand (RH), unless
otherwise indicated.
When holding, pressing or driving is required, use
soft metal vise jaw protectors or wood for protection
of parts. Use a suitable mandrel (one that will contact
only the bearing race) when pressing or driving
bearings.
Whenever compressed air is used to dry a part, be
sure that no water is present in air line.
BEARINGS
Upon disassembly of gear housing, all bearings must
be cleaned and inspected. Clean bearings with
solvent and dry with compressed air. Air should be
directed at the bearing so that it passes thru the
bearing. DO NOT spin bearing with compressed air,
as this may cause bearing to score from lack of
lubrication. After cleaning, lubricate bearings with
Quicksilver Gear Lubricant. DO NOT lubricate
tapered bearing cups until after inspection.
Inspect all bearings for roughness, catches and
bearing race side wear. Work inner bearing race
in-and-out, while holding outer race, to check for side
wear.
When inspecting tapered bearings, determine
condition of rollers and inner bearing race by
inspecting bearing cup for pitting, scoring, grooves,
uneven wear, imbedded particles and/or
discoloration from overheating. Always replace
tapered bearing and race as a set.
Roller bearing condition is determined by inspecting
the bearing surface of the shaft that the roller bearing
supports. Check shaft surface for pitting, scoring,
grooving, imbedded particles, uneven wear and/or
discoloration from overheating. The shaft and
bearing
must be replaced, if the conditions described
are found.
SHIMS
Keep a record of all shim amounts and location
during disassembly to aid in reassembly. Be sure to
follow shimming instructions during reassembly, as
gears must be installed to correct depth and have the
correct amount of backlash to avoid noisy operation
and premature gear failure.
SEALS
As a normal procedure, all O-rings and oil seals
SHOULD BE REPLACED without regard to
appearance. To prevent leakage around oil seals,
apply Loctite 271 to outer diameter of all metal case
oil seals. When using Loctite on seals or threads,
surfaces must be clean and dry. To ease installation,
apply Quicksilver 2-4-C w/Teflon Marine Lubricant on
all O-rings. To prevent wear, apply Quicksilver 2-4-C
w/Teflon Marine Lubricant on l.D. of oil seals.
To prevent corrosion damage after reassembly,
apply Quicksilver 2-4-C w/Teflon Marine Lubricant to
external surfaces of bearing carrier and cover nut
threads prior to installation.