• Mercruiser Alpha 1 Gen 2 upper gearcase

Alpha One generation 2 upper gearcase years 1998 and up

Updated April 26 2026

• SEI Alpha 1 Gen 2 upper gearcase drawing
• Compatible with all stern drive models 1998 and up
• Gear sets, bearing, drive shaft and U joints
• Mercruiser Alpha One Generation 2 OEM numbers for easy cross reference

Mercruiser Alpha 1 Gen 2 1998 up

Photo

Description / OEM #

Price
(USD)

Price (Canadian)

29020 Driveshaft housing assembly

#1 Driveshaft housing assembly

1547 – 861063 A4

$1,105.95

$1,459.89

80420 O-ring

#2

O-ring

25 – 32546

$4.95

$4.89

23261 Shim

#3

 

Shim

GLM Marine bearing number 21511 bearing.

15 – 32563 A1

$5.95

$ 16.89

21511 Tapered roller bearing assembly

#4

 

Bearing assembly

 

(O.D. 1-25/32)

(1996 and up)

31 – 32575 A1

$8.95

$ 15.89

11131 Mercruiser Alpha 1 Gen 2 Drive shaft

#5

Mercruiser Alpha 1 Gen 2

Drive shaft

45 – 55796

$106.95

$ 73.89

11214 Gear set

#6

 

Gear set (1.47 Ratio)(20 – 22)

 

43 – 853641 A2

$508.95

$ 453.89

11222 Gear set 24-24 ratio 1998 up

#6

 

Gear set

 

(2.00 / 1.62 Ratio) (24 – 24)

 

43 – 853640 A2

$508.95

$ 416.89

11233 Gear set OEM 43-853643A2

#6

 

Gear set

 

(1.81 Ratio) (17 – 19)

 

43 – 853643 A2

$466.95

$ 390.89

11244 Gen 2

#6

 

Gear set (2.40 / 1.94 Ratio)

 

(20-24)

 

43 – 853642 A2

$508.95

$ 302.89

21540 Roller bearing

#7

 

Roller bearing

 

(1.62, 1.81, 1.94, 2.00, 2.40 Ratio)

 

31 – 35990  A1

$30.95

$ 50.89

21560 Roller bearing

#7

Roller bearing

(1.47 Ratio)

31 – 32573 A1

$40.95

$ 68.89

23270 Shim

#8

Shim

15 – 36178 A1

$9.95

$ 19.89

28070 Alpha 1 Gen 2 internal ring 1998 up

#10

 

U-joint assembly

 

(Internal lock ring style)

 

814819 A7

$501.95

$ 786.89

28080 Drive shaft parts with external lock ring

#10

 

U-joint assembly

 

(External lock ring style)

 

864281 A2

$553.95

$ 858.89

81180 O-ring

#11

 

O-ring

 

25 – 25439

$4.95

$4.89

82150 O-ring

#11

 

O-ring

 

25 – 35027

$4.95

$4.89

28315 Yoke - long

#12

 

Yoke – Long

 

(Internal lock ring style)

 

814819 A3

$103.95

$ 191.89

28316 Yoke - long

#12

 

Yoke – Long

 

(External lock ring style)

 

864281 A01

$175.95

$ 271.89

28030 U-joint

#13

 

 U-joint

 

 (Internal lock ring style)

 

75832 T1

$44.95

$ 68.89

28040 U joint

#13

U-joint

(External lock ring style)

 

865496 A01

$100.95

$ 159.89

28100 Socket

#14

 

Socket

 

(Internal lock ring style)

 

39383 – 1

$64.95

$ 115.89

28110 Socket

#14 Socket (External lock ring style)

86550 3T

$50.95

$ 79.89

28312 Yoke

#15

 

Yoke

 

(Internal lock ring style)

 

853635

$123.95

$ 191.89

28322 Yoke

#15

 

Yoke

 

(External lock ring style)

 

864282T

$106.95

$ 165.89

28350 Mercruiser Retainer

#16

 

Mercruiser Retainer

 

816811 – 2

$22.95

$ 37.89

28390 Ring

#17

 

Ring

 

35983

$11.95

$ 16.89

82380 O-ring

#18

 

O-ring

 

25 – 70937

$4.95

$4.89

28370 Alpha 1 Gen 2 Carrier assembly

#19 Alpha 1 Gen 2 Carrier assembly

66081 A2

$36.95

$ 66.89

85030 Oil seal

#20 Oil seal

26 – 826894

$12.95

$ 24.89

21522 Bearing set

#21

 

Mercruiser Roller bearing kit

 

 

31 – 30894 A5

$122.95

$ 167.89

23280 Shim

#22

 

Shim

 

15 – 35980 A1

$10.95

$ 27.89

28380 Spacer

#23

 

Spacer

 

15 – 71013

$4.95

$ 10.89

28330 Tension washer

#24

 

Tension washer

 

12 – 45810

$4.95

$4.89

28360 Lock nut

#25

 

Lock Nut

 

11 –  22339

$4.95

$ 5.89

22420 Alpha 1 Gen 2 Screw kit

#26

 

Alpha 1 Gen 2

Screw kit

 

10 – 79953 Q2

$4.95

$4.89

31170 Washer

#27

Washer

12 – 19183 – 2

$4.95

$4.89

28410 Locknut

#28

Locknut

11 – 817618

$4.95

$ 6.89

28420 Washer

#29

Washer

12 – 45176

$4.95

$4.89

28430 Bolt OEM 10-816601

#30

Bolt

10  –  816601

$4.95

$ 6.89

12930 Spring kit

#31 Spring kit

24 – 17997 A1

$4.95

$6.95

12831 Alpha 1 gen 2 grommet OEM 26-88397

#32

Grommet

26  –  88397

$4.95

$ 7.89

12829 Guide tube

#33

Guide tube

32 – 8602200

$9.95

$ 17.89

12711 Anode

#34

Anode

821629 Q1

$27.95

$ 40.89

05009 Lockwasher

#35 Lockwasher

13 – 78968

$4.95

$4.89

22440 Screw

#36 Screw

10 – 28668

$4.95

$4.89

28300 Screw

#37

Screw

10 – 98794

$4.95

$4.89

12965 Plug

#38

Plug

861738

12966 Plug

#39

Plug

19 – 33297

$4.95

$4.89

28402 Mercruiser Alpha 1 Gen 2 Cover assembly

#40 Mercruiser Alpha 1 Gen 2 Cover assembly

828692 A1

$190.95

$ 277.89

10991 Filler wall

#41 Filler wall

815932

$4.95

$4.89

12663 Wear pad

#42

 

Wear pad – Port

 

814386

$4.95

$4.89

12664 Wear pad

#42 Wear pad – Starboard

814387

$4.95

$4.89

21820 Bearing

#44

 

Bearing

 

31 – 30894 A1

$35.95

$ 61.89

87501 Gearcase seal kit

#45

 

Gearcase seal kit

 

26 – 88397 A1

$33.99

$47.99

39622 Mercruiser Mounting kit

#46

 

Mercruiser Mounting kit

 

27 – 94996 T2

$9.95

$ 9.89