ALPHA DRIVE UNIT

ALPHA DRIVE UNIT TOOLS 1

73658

90-806737--2 SEPTEMBER 2001 Page 1-1

ALPHA DRIVE UNIT

Alpha Drive Unit Tool Application Chart

MC-1,
Alpha
R-MR
Part Number Page Description One
Alpha
Gen II
One
91-805475A1 1-5 Alignment Tool Assembly • •
91-78473 1-5 Backlash Indicator • •
91-53459 1-5 Backlash Indicator Rod • •
91-18605A2 1-5 Bearing Adaptor Installation Tool • •
Bearing Carrier Retainer Nut
91-61069T 1-6 • •
Wrench
91-33493T 1-6 Bearing Cup Driver •
91-34379T 1-6 Bearing Cup Driver •
91-36577T 1-6 Bearing Cup Driver •
91-38918T 1-7 Bearing Cup Driver •
91-808053T 1-7 Bearing Cup Driver •
91-33489 1-7 Bearing Driver • •
91–32325T 1-7 Bearing Driver Head • •
91-38628T 1-8 Bearing Installation Tool •
Bearing Removal and Installation
91-31229A7 1-8 • •
Tool Assembly
91-17256 1-8 Bearing Retainer Wrench • •
12-54048 1-8 Belleville Washer • •
91-45497A1 1-9 Bellows Expander Tool •
91-805057A2 1-9 Bushing Installation Tool • •
91-58222A1 1-9 Dial Indicator • •
91-83155 1-9 Dial Indicator Adaptor Kit •
91-89897 1-10 Dial Indicator Holding Tool •
91-56775T 1-10 Drive Shaft Adaptor • •
Drive Shaft Bearing Retainer
91-43506T 1-10 • •
Wrench
91-14311A2 1-11 Drive Shaft Bearing Preload Tool • •
91-36569T 1-11 Driver Head •
91-37323 1-11 Driver Rod • •
91-44357Q2 1-11 Flushing Device • •
91-815850 1-12 Forward Gear Assembly Tube • •
Forward Gear Bearing Cup
91-31229 1-12 • •
Puller Shaft

Page 1-2 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Alpha Drive Unit Tool Application Chart

MC-1,
Alpha
R-MR
Part Number Page Description One
Alpha
Gen II
One
Gimbal Bearing Installation Collar
91-30366T1 1-12 • •
Number 3
91-816243 1-12 Guide Plate • •
91-90774 1-13 Guide / Puller Tool •
11-24156 1-13 Hex Nut • •
91-78310 1-13 Hinge Pin Tool • •
91-37299Q2 1-14 Lube Gun •
91-877528-1 1-14 MCM Tool Overlay Kit • •
91-15755T 1-14 Needle Bearing Driver • •
91-33491 1-14 Needle Bearing Driver •
91-33492T 1-15 Needle Bearing Driver •
Needle Bearing Driver, Pilot
91-37324T 1-15 •
Washer
Needle Bearing Installation Tool,
91-807944T 1-15 •
Reverse Gear
91-816245 1-15 Needle Bearing Removal Tool • •
91-31108T 1-16 Oil Seal Driver • •
91-817569T 1-16 Oil Seal Driver •
91-36571T 1-16 Pilot Washer •
91-37350T 1-16 Pilot Washer • •
91-56048T 1-17 Pinion Gear Shimming Tool • •
91-61067A3 1-17 Pinion Nut Adaptor •
91-95639 1-17 Pipe Tap •
91-29310 1-17 Plate Puller • •
91-806908A1 1-18 Power Steering Adaptor Kit •
91-38053A4 1-18 Power Steering Test Gauge Kit • •
91-61077T 1-18 Propeller Shaft Adaptor • •
91-38919 1-18 Puller Head •
91-63616T 1-19 Puller Head • •
91-34570 1-19 Puller Jaws • •

90-806737--2 SEPTEMBER 2001 Page 1-3

ALPHA DRIVE UNIT

Alpha Drive Unit Tool Application Chart

MC-1,
Alpha
R-MR
Part Number Page Description One
Alpha
Gen II
One
91-816242 1-19 Puller Jaws • •
91-85716 Puller Jaw Assembly
1-19 • •
91-46086A1 Puller Bolt
Reverse Gear Needle Bearing
816244 1-20 • •
Driver
Roller Bearing Removal and
91-37292 1-20 • •
Installation Tool
91-806928A1 1-20 Seal and Bushing Installation Tool •
91-43591T 1-20 Seal Driver • •
91-44110T 1-21 Seal Driver • •
91-12037 1-21 Shift Cable Tool • •
91-31107T 1-21 Shift Shaft Bushing Tool •
91-809815A1 1-21 Shift Shaft Slide Stabilizer • •
75104A7 1-22 Shift Shaft Tool •
91-60523 1-22 Shimming Tool, Drive Gear • •
91-60526T 1-22 Shimming Tool, Driven Gear • •
91-854377 1-22 Shimming Tool, Driven Gear •
91-818162 1-23 Sleeve Installation Tool •
91-818169T 1-23 Sleeve Removal Tool •
91-34569A1 1-23 Slide Hammer Puller • •
91-37240A1 1-23 Snap Ring Pliers •
91-821709T 1-24 Spanner Wrench • •
91-38277A2 1-24 Tab Washer Pliers •
91-63209 1-24 Torch Lamp • •
91-66274 1-24 Torque Wrench, lb-in. • •
91-43693A2 1-24 Transom Cutout and Drill Fixture • •
91-52915A6 1-25 Trim Pump Test Gauge Kit • •
91-38756 1-25 U-joint Adaptor • •
91-37241 1-25 Universal Puller Plate • •
Upper Drive Shaft Housing Seal
91-817570T 1-25 •
Driver
91-34961 1-26 Washer • •
91-821571A1 1-26 Water Pump Alignment Pins •

Page 1-4 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Alignment Tool Assembly 91-805475A1

Description: Aligns the engine and drive

unit during installation.

73699

Backlash Indicator 91-78473

Description: Checks the gear backlash on

the Alpha drive units using 14/28 tooth count
and gear housing.

75943

Backlash Indicator Rod 91-53459

Description: Checks the gear backlash on

the TR, TRS, MC-1, R-MR, Alpha One and
Alpha One Gen II drive units.

73455

Bearing Adaptor Installation

91-18605A2
Tool

Description: Presses the reverse gear

bearing adaptor into the gear housing of the
Alpha One and Alpha One Gen II counter
rotating gear cases.

73816

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ALPHA DRIVE UNIT

Bearing Carrier Retainer

91-61069T
Nut Wrench

Description: Removes and installs the

bearing carrier retainer nuts on the MC-1,
R-MR, Alpha One and Alpha One Gen II
drive units.

73605

Bearing Cup Driver 91-33493T

Description: Installs the upper drive shaft

bearing cup in the drive shaft housing of the
MC-1, R-MR and Alpha One drive units.

73491

Bearing Cup Driver 91-34379T

Description: Installs the drive shaft bearing

cup in gear the housing of the MC-1, R-MR
and Alpha One drive units.

73659

Bearing Cup Driver 91-36577T

Description: Installs the forward gear

bearing cup in the gear housing of the MC-1,
R-MR, Alpha One and Alpha One Gen II with
bearing cup diameter of 3.500 in. 89 outside
diameter (O.D.).

73492

Page 1-6 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Bearing Cup Driver 91-38918T

Description: Installs the bearing cup in the

top cover of the drive shaft housing of the
MC-1, R-MR and Alpha One drive units.

73490

Bearing Cup Driver 91-808053T

Description: Use to install a new smaller

outside diameter top cover bearing on the
Alpha One Gen II drive units.

75945

Bearing Driver 91-33489

Description: Installs the small roller

bearing in the gimbal housing of the MC-1,
R-MR and Alpha One drive units.

73468

Bearing Driver Head 91-32325T

Description: Installs the gimbal bearing in

the MC-1, R-MR, Alpha One and Alpha One
Gen II drive units. Use with 91-30366T1
Gimbal Bearing Installation Collar Number
3.

73818

90-806737--2 SEPTEMBER 2001 Page 1-7

ALPHA DRIVE UNIT

Bearing Installation Tool 91-38628T

Description: Installs the pinion bearing on

the MC-1, R-MR and Alpha One drive units.

74193

Bearing Removal and

91-31229A7
Installation Tool Assembly
Description: Removes and installs the
bearings in the MC-1, R-MR, Alpha One and
Alpha One Gen II gear cases. Includes:

91-36569T Driver Head

91-37323 Driver Head Rod
11-24156 Nut
91-36571T Pilot Washer
91-29610 Pilot Plate
91-38628T Puller/Driver Head
91-30366T1 Mandrel
91-29310 Plate
91-32325T Driver Head
91-31229 Puller Shaft 70615
12-34961 Washer

Bearing Retainer Wrench 91-17256

Description: Removes and installs the

drive shaft bearing retainer on the MC-1,
R-MR and all Alpha drive units.

73482

Belleville Washer 12-54048

Description: Use with the 91-61067A3

Pinion Nut Adapter and a propeller nut to
check the reverse gear lash on the MC-1,
R-MR, Alpha One and Alpha One Gen II
drive units.

75940

Page 1-8 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Bellows Expander Tool 91-45497A1

Description: Installs the exhaust bellows

on the MC-1, R-MR and Alpha One drive
units.

73430

Bushing Installation Tool 91-805057A2

Description: Installs the shift shaft upper

bushings in the R-MR, Alpha One and
earlier models of the Alpha One Gen II
transom assembly.

73821

Dial Indicator 91-58222A1

Description: Measures gear the backlash

on all drive units.

73429

Dial Indicator Adaptor Kit 91-83155

Description: Attaches the dial indicator to

the gear case when checking backlash on
MC-1, R-MR and Alpha One Gen II drive
units.

73643

90-806737--2 SEPTEMBER 2001 Page 1-9

ALPHA DRIVE UNIT

Dial Indicator Holding Tool 91-89897

Description: Secures the dial indicator to

gear housing when checking backlash on
the MC-1, R-MR and Alpha One drive units.

73648

Drive Shaft Adaptor 91-56775T

Description: Provides a wrench surface to

turn the drive shaft on the MC-1, R-MR,
Alpha One and Alpha One Gen II drive units.

73640

Drive Shaft Bearing Retainer

91-43506T
Wrench

Description: Removes and installs the

threaded bearing retainer on all Alpha drive
units.

73608

Page 1-10 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Drive Shaft Bearing Preload

91-14311A2
Tool

Description: Preloads the drive shaft

bearing when checking pinion height and
backlash on the MC-1, R-MR, Alpha One
and Alpha One Gen II drive units.
NOTE: This tool is also used on the Mercu-
ry and Mariner V-6 gear cases. Check your
inventory before purchasing.

73885

Driver Head 91-36569T

Description: Removes the pinion bearing

from the MC-I, R, MR, Alpha One, and Alpha
One Gen II drive units.

74185

Driver Rod 91-37323

Description: Use with various drivers to

install bearings on the Alpha One Gen II
gear cases.

74184

Flushing Device 91-44357Q2

Description: Attaches to the drive unit

water intake, to provide a fresh water
connection when flushing the cooling
system or operating the engine with the
power package out of the water.

73440

90-806737--2 SEPTEMBER 2001 Page 1-11

ALPHA DRIVE UNIT

Forward Gear Assembly Tube 91-815850

Description: Installs and removes the

forward gear of the Alpha One and Alpha
One Gen II counter rotating gear cases.

73486

Forward Gear Bearing Cup

91-31229
Puller Shaft

Description: 5/8 in. x 18 in (15.875 mm)

long threaded rod.

75928

Gimbal Bearing Installation

91-30366T1
Collar Number 3

Description: Use with 91-29310 Plate

Puller, 91-37323 Driver Rod and 91-32335T
Bearing Head to install the gimbal bearing in
Alpha and MC-1 drive units.

75931

Guide Plate 91-816243

Description: Centers the rod used to drive

in the front bearing on the Alpha One Gen II
counter rotating gear case.

73483

Page 1-12 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Guide \ Puller Tool 91-90774

Description: Presses the bearing cone

onto the Alpha One Gen II drive shaft
housing pinion gear.

73823

Hex Nut 11-24156

Description: Use with 91-31229 Forward

Gear Bearing Cup Puller Shaft to pull the
bearing assembly.

75930

Hinge Pin Tool 91-78310

Description: Removes and installs the

hinge pins from all Mercury MerCruiser
drive units.

73443

Lube Gun 91-37299Q2

Description: Allows easy access to grease

fittings.

73674

90-806737--2 SEPTEMBER 2001 Page 1-13

ALPHA DRIVE UNIT

MCM Tool Board Overlay Kit 91-877528-1

Description: MCM Tool Overlay Kit (sheet

numbers 10-20 ) contains 11 overlay sheets
and hooks indicating locations for all the
Mercury MerCruiser gasoline engines and
sterndrive units active service tools.
Includes 91-883983 MCM Tool Board
Overlay Update Kit.

77976

Needle Bearing Driver 91-15755T

Description: Installs needle bearings in

MC-1, R-MR, Alpha One and Alpha One
Gen II bearing carriers.

73815

Needle Bearing Driver 91-33491

Description: Installs the needle bearing in

the forward gear, removes and installs the
seals and bearing in the gimbal housing of
the MC-1, R-MR and Alpha One drive units.

73471

Needle Bearing Driver 91-33492T

Description: Removes and installs the

lower swivel pin needle bearings in the
gimbal ring on the MC-1, R-MR and Alpha
One drive units.

73470

Page 1-14 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Needle Bearing Driver, Pilot

91-37324T
Washer

Description: Used to pilot the threaded rod

when installing the pinion bearing in the
MC-1, R-MR, and Alpha One drive units.

75938

Needle Bearing Installation

91-807944T
Tool, Reverse Gear

Description: Use to install the needle

bearing in the reverse gear on the Alpha
One Gen II counter rotation drive units.

75944

Needle Bearing Removal Tool 91-816245

Description: Removes the needle bearings

from the back adaptor of the Alpha One Gen
II counter rotating gear case.

73448

Oil Seal Driver 91-31108T

Description: Installs the oil seals in the

bearing carrier on the MC-1, R-MR, Alpha
One and Alpha One Gen II drive units.

73651

90-806737--2 SEPTEMBER 2001 Page 1-15

ALPHA DRIVE UNIT

Oil Seal Driver 91-817569T

Description: Installs and removes the

Alpha One Gen II counter rotating bearing
carrier seals; also, install seals in the drive
shaft seal carrier.

73450

Pilot Washer 91-36571T

Description: Use as a centering guide to

install the pinion bearing in the MC-1, R-MR,
Alpha One and Alpha One Gen II drive units.

74187

Pilot Washer 91-37350T

Description: Use with 91-31229A7

Universal Bearing Puller Kit.

75939

Pinion Gear Shimming Tool 91-56048T

Description: Measures the pinion height of

the MC-1, R-MR, Alpha One and Alpha One
Gen II drive units.

73436

Page 1-16 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Pinion Nut Adaptor 91-61067A3

Description: Holds the pinion nut when

removing the pinion gear and drive shaft on
the MC-1, R-MR and Alpha One drive units.

73442

Pipe Tap 91-95639

Description: Taps the bell housing for shift

cable installation on the MC-1, R-MR and
Alpha One drive units.

73475

Plate Puller 91-29310

Description: Use as a guide to remove and

install the gimbal bearing on MC-1, R-MR,
Alpha One and Alpha One Gen II drive units.

74190

Power Steering Adaptor Kit 91-806908A1

Description: Adapts Power Steering Test

Gauge 91-38053A4 to test later model
power steering control valves.

74168

90-806737--2 SEPTEMBER 2001 Page 1-17

ALPHA DRIVE UNIT

Power Steering Test Gauge Kit 91-38053A4

Description: Tests power steering system

pressure.

74167

Propeller Shaft Adaptor 91-61077T

Description: Provides a wrench surface to

turn the propeller shaft on the MC-1, R-MR,
Alpha One and Alpha One Gen II drive units.

73427

Puller Head 91-38919

Description: Removes the swivel pins from

the R-MR and Alpha One gimbal rings.

73820

Puller Head 91-63616T

Description: Removes the upper swivel

shaft on MC-1, R-MR, Alpha One and Alpha
One Gen II gimbal rings.

73428

Page 1-18 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Puller Jaw 91-34570

Description: Replacement jaw for the

91-34569A1 Slide Hammer Puller Tool.

77890

Puller Jaw 91-816242

Description: Use with either the two prong

or three prong puller on all Mercury
Mercruiser drive units.

75946

Puller Jaw Assembly 91-46086A1

Puller Bolt 91-85716

Description: Removes bearing carrier on

the MC-1, R-MR, Alpha One and Alpha One 91-46086A1
Gen II drive units.
91-85716

73599

Reverse Gear Needle Bearing

91-816244
Driver

Description: Installs the needle bearings

into the reverse gear of the Alpha One and
Alpha One Gen II counter rotating gear
case.

73488

90-806737--2 SEPTEMBER 2001 Page 1-19

ALPHA DRIVE UNIT

Roller Bearing Removal and

91-37292
Installation Tool

Description: Part of 91-31229A7 Bearing

Removal and Installation Tool Assembly,
use with the threaded puller rod or driver
rod.

75935

Seal and Bushing Installation

91-806928A1
Tool

Description: Installs the shift shaft

bushings in the Alpha One Gen II drives with
serial number 0F094775 and Above.

74169

Seal Driver 91-43591T

Description: Installs the upper drive shaft

oil seal on the Alpha One and Alpha One
Gen II drive units.

73467

Seal Driver 91-44110T

Description: Installs the oil seals in the

water pump base on the Alpha One and
Alpha One Gen II drive units.

73472

Page 1-20 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Shift Cable Tool 91-12037

Description: Installs the shift shaft upper

bushing in the R-MR, Alpha One and the
earlier Alpha One Gen II transom
assemblies.

73459

Shift Shaft Bushing Tool 91-31107T

Description: Removes and installs the shift

shaft bushing in the gear case on the MC-1,
R-MR and Alpha One drive units.

73658

Shift Shaft Slide Stabilizer 91-809815A1

Description: Use to hold the Alpha shift

shaft slide in the proper position as the drive
unit is installed onto the bell housing studs.
73608

75199

Shift Shaft Tool 75104A7

Description: Manually shifts the MC-1,

R-MR, Alpha One and Alpha One Gen II
drive units. The tool connects onto the gear
housing shift shaft when the gear housing is
separated from the drive shaft housing.

74186

90-806737--2 SEPTEMBER 2001 Page 1-21

ALPHA DRIVE UNIT

Shimming Tool, Drive Gear 91-60523

Description: Measures the upper drive

gear clearance on the MC-1, R-MR, Alpha
One and Alpha One Gen II drive units.

73445

Shimming Tool, Driven Gear 91-60526T

Description: Measures the upper driven

gear clearance on the MC-1, R-MR, Alpha
One and Alpha One Gen II drive units.

73452

Shimming Tool, Driven Gear 91-854377

Description: Use to shim the driven gear on

the Alpha One Gen II starting with Serial
Number 0L100009 and above. Can be
identified by the letters “A, B, C.”

75947

Sleeve Installation Tool 91-818162

Description: Installs the aluminum sleeve

in the U-joint bellows of all the Alpha One
Gen II drive units.

73485

Page 1-22 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Sleeve Removal Tool 91-818169T

Description: Removes the aluminum

sleeve from the U-joint bellows of the Alpha 7
One Gen II drive units.

73484

Slide Hammer Puller 91-34569A1

Description: Removes the bearings and

bearing cups.
91-34570 Replacement jaw.

73655

Snap Ring Pliers 91-37240A1

Description: Removes the snap ring

located at the gimbal housing bearing on the
MC-1 drive units.

73431

Spanner Wrench 91-821709T

Description: Removes the trim cylinder
end cap on all Mercury MerCruiser, Mercury
and Mariner trim cylinders. Uses
interchangeable pin sets:
91-811907 Large pin set 0.235 in. (5.97 mm)
91-811908 Medium pin set 0.180 in.
(4.57mm)
91-811909 Small pin set 0.150 in. (3.81 mm) 71233

90-806737--2 SEPTEMBER 2001 Page 1-23

ALPHA DRIVE UNIT

Tab Washer Pliers 91-38277A2

Description: Bends the propeller tab

washer tangs off of tab nut on the MC-1,
R-MR, and Alpha One drive units.

73653

Torch Lamp 91-63209

Description: 120v Torch Lamp, heats the
bearing bores to make bearing removal and
installation easier.

91-63210 Replacement bulb 120v

NOTE: 91-74042 Torch Lamp 240v is no
longer available. 88-68664 Replacement
240v bulb is available.. 73437

Torque Wrench, lb-in. 91-66274

Description: Sets torques from 9 to

150 lb-in; 3/8 in. drive.

73430

Transom Cutout and Drill

91-43693A2
Fixture

Description: Use for cutting and drilling the

boat transom for sterndrive installation.

22056

Page 1-24 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

Trim Pump Test Gauge Kit 91-52915A6

Description: Use in various trim pump

tests.

73835

U-joint Adaptor 91-38756

Description: Supports the yoke when

disassembling U-joint on all the drive units.

74229

Universal Puller Plate 91-37241

Description: Removes gears and

bearings.

73652

Upper Drive Shaft Housing 91-817570T

Seal Driver

Description: Installs the seals in the Alpha

One Gen II upper drive shaft housing.

73449

90-806737--2 SEPTEMBER 2001 Page 1-25

ALPHA DRIVE UNIT

Washer 12-34961

Description: Use on the threaded puller rod

between the nut and plate when removing
bearings.

75934

Water Pump Alignment Pins 91-821571A1

Description: Aligns the Alpha One Gen II

water pump during installation.

73822

Page 1-26 90-806737--2 SEPTEMBER 2001

 ALPHA DRIVE UNIT

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