Reverse Gear - Mercury 150 EFI Service Manual

NOTE: Bearing Preload Tool (91-14311A1) should remain installed on driveshaft after
setting pinion gear depth as it is required to properly check forward gear and reverse gear
backlash.

Reverse Gear

DETERMINING REVERSE GEAR BACKLASH
NOTE: Reverse gear backlash is adjustable using shims; it can be checked as follows:
1. Install Driver Tool (91-18605) into reverse gear assembly.
2. Slide Pilot Ring (91-18603) over driver tool and seat pilot ring against inner ledge in
gear case.
3. Thread Retainer (91-18604) into gear case cover nut threads.
4. Torque Screw (91-18602) to 45 Ib. in. (5 Nm) against driver tool.
a -
b -
c -
d -
e -
5. Thread stud adapter [from Bearing Preload Tool (91-14311A1)] all the way onto stud.
6. Install: Backlash Indicator Tool (91-78473)
7. Position dial indicator pointer on line marked "1" on Backlash Indicator Tool, if gear
ratio is 1.87:1 (15 teeth on pinion gear), or on line marked "2" on Backlash Indicator
Tool, if gear ratio is 2:1 (14 teeth on pinion gear).
8. Lightly turn driveshaft back-and-forth (no movement should occur at propeller shaft).
90-883728 JULY 2001
d
d
b
b
a
a
e
e
Driver Tool (91-18605)
Pilot Ring (91-18603)
Inner Ledge
Retainer (91-18604)
Screw (91-18602) [Torque to 45 lb. in. (5 Nm)]
Dial Indicator Holder (91-89897)
Dial Indicator (91-58222A1)
LEFT HAND NON-RATCHETING
c
c
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