Mercury 40 Service Manual page 552

BIGFOOT GEAR HOUSING
Pinion Gear Depth and Forward Gear Backlash
DETERMINING PINION GEAR DEPTH
NOTE: Read entire procedure before attempting any change in shim thickness.
IMPORTANT: Forward gear assembly must be installed in gear housing when check-
ing pinion gear depth or an inaccurate measurement will be obtained.
1. Clean the gear housing bearing carrier shoulder and diameter.
2. With gear housing positioned up right (driveshaft vertical), install Bearing Preload Tool
(91-14311A2) over driveshaft in sequence shown.
a - Adaptor: Bearing surfaces clean and free of
nicks
b - Thrust Bearing: Oiled and able to move freely
c - Thrust Washer: Clean and free of nicks and
bends
d - Spring
3. Measure distance between top of nut and bottom of bolt head.
4. Increase distance by 1 in. (25.4 mm).
5. Rotate driveshaft 5 to 10 revolutions. This should properly seat driveshaft tapered roller
bearing.
a -
b -
c -
Page 6B-46
h
e
f
d
c
b
1 in. (25.4 mm)
Nut
Bolt Head
g
h
c
b
a
e - Nut: Threaded all-the-way onto bolt
f - Bolt: Held snug against spring
g - Sleeve: Holes in sleeve must align with set
screws
h - Set Screw (2): Tightened against driveshaft,
bolt should not slide on driveshaft.
a
19884
90-828631R3 MARCH 1999