Mercury 25 EFI Service Manual page 442

Gear Housing
6. Attach the backlash indicator arm to the driveshaft.
k
m
l
k
Description
Pinion nut
Water pump cover screws
Backlash Preload Tool
Backlash Indicator Arm
Driveshaft Holding Tool
Pinion Nut Tool
7. Attach the dial indicator to the threaded rod (obtain locally) and align the dial indicator shaft with the V notch on the
indicator arm.
8. Lift up on the driveshaft and lightly rotate the driveshaft back and forth. Check the dial indicator for the amount of backlash.
Adding shims between the forward gear and the forward gear bearing reduces backlash. Removing shims increases
backlash.
9. After the correct forward gear backlash has been obtained, remove the pinion gear nut. Remove any oil from the pinion nut
threads. Apply Loctite 271 Threadlocker to the pinion nut threads and reinstall the pinion gear and pinion nut. Torque the
pinion nut to specification.
Tube Ref No.
Loctite 271 Threadlocker
7
Description
Pinion nut
10. Remove the Backlash Indicator Arm from the driveshaft.
11. Remove the Dial Indicator Assembly.
Page 6A-36
a
j
Description
© 2016 Mercury Marine
b
c
d
e
f
j
i
91‑895195004
91‑803133 12
91‑853996 14
91‑853996 12
Where Used
Pinion nut threads
a - Backlash Indicator
Arm
b - Water pump cover
c - Water pump base
d - Shims
e - Driveshaft bearing
f - Forward gear
assembly
g - Collar (part of
Backlash Preload
Tool Kit ‑ O‑ring is
located under collar)
h - O‑ring
i - Tapered washers
j - Backlash Preload
Tool
k - Bearing carrier
attaching screws
l - Plate (part of
h
g
Backlash Preload
Tool Kit)
m - Jam nuts
16394
Nm lb. in.
35
6 53
92-809819
Nm lb. in.
35
90-8M0105568 eng MARCH 2016
lb. ft.
25
Part No.
lb. ft.
25