Mercruiser Alpha 1 parts drawing *Upper gearcase

GLM Marine aftermarket upper gearcase stern drive parts Comprehensive exploded view outdrive tech drawing

Last updated on 8/12/2023, 1:17:46 AM

  • All GLM products are completely compatible and interchangeable with OEM parts. GLM has committed to producing high quality and cost effective aftermarket parts for the past two decades
  • If help or part numbers are required, contact our service tech for advice troubleshooting your sterndrive unit at (416) 751-7326
  • R MR, Mercruiser Alpha one and 2 repair tools
  • Bell housing drawing

Mercruiser Alpha One upper gearcase

Click on video for upper gearcase repair help

87500 Seal kit parts

A
P/N 87500
 GLM Marine aftermarket seal kit for upper gear-case $24.99

39622 OMC Bell housing gasket kit

B
P/N 39622 OEM 27-94996Q2 $9.95 (This gasket is required to install the outdrive back onto the bell housing)

19000 Upper gearcase

1A P/N 19000 Empty drive shaft housing / 1547-9412A18

upper gear case assembly 20 22

1C
P/N SE106-116 Complete SEI Marine upper housings (all ratios available) (new) 1547-9412A20 $1199.99

28400 cover assembly

P/N 28400 Cover assembly with parts
94998A4 Top comes with P/N 21511,
shim P/N 23261 and 4 bolts $125.99
 
*Compatible with models from late 1983 to 1990 only

21510 Alpha 1 bearing cover 1-15-16

5A
P/N 21510
 upper cover tapered assembly O.D. 1-15/16″ OEM 31-61100A1 $33.99

21511 Alpha 1 bearing cover 1 25-32

5B
P/N 21511
 Roller bearing for upper cover assembly O.D. 1-25/32″
31-32575A1 $12.99

11130 Alpha 1 upper drive shaft

6
P/N 11130 Upper drive shaft / 45-55796 $96.99

80190 Alpha 1 O-ring

7
P/N 80190 vertical drive shaft o ring (5 units) $4.99

11210 Alpha 1 gear set V8 22-20 gear ratio

8A
P/N 11210 
V8 heavy duty 20/22 Gears for Alpha 1 and generation 2 with HD P/N 21560 included / 43-18411A2
$399.99 ratio 1.50-1.47 ratio / 20/22 gears

11220 Alpha 1 gear set 24-24 1970-1997 6 cylinder

8B
P/N 11220
 6 Cylinder inline upper gear set (1.65 or 1.62 Ratio) 24-24 years 1970 to 1997 / 43-45814A5 $275.99

11230 Alpha 1 gear set ratio 17-19 V-6 470-485

8C
P/N 11230
 V6 and 470/485 model upper gear set ratio. 1.81-1.84 / 17/19 gears / 43-75325A3 $337.99

11240 Alpha 1 gear set 20-24 ratio 1.98 4 cylinder

8D
P/N 11240
 4 Cylinder inline, gear ratio 20/24 upper unit gear set (1.98 or 1.94 Ratio) 43-55778A3 $332.99

21560 Alpha bearing for 1.50 gear ratio

9A
P/N 21560 bearing tapered roller (1.50 ratio) 31-32573A1 $47.99

21540 Alpha bearing 1.65 1.84 1.98 gear ratio

9B
P/N 21540 roller type (1.65, 1.84, 1.98 Ratio), replaces Mercury part number 31-35990A1 $39.99

21550 - 1.32 ratio bearing

9C
P/N 21550
 Roller bearing for Mercruiser Alpha 17/19 gear set (1.32 Ratio) 31-66818A1 $75.95

23270 Alpha 1 driven gear bearing shim

10
P/S 23270
 Shims / 15-36178A1 $11.99

85020 Oil seal upper gearcase driven gear

11
P/N 85020
 Oil seal $11.95

85060 OMC Alpha 1 Oil seal

12
P/N 85060
 Oil seal $11.99

28050 Mercruiser socket yoke drive shaft nut

14
P/N 28050 
U joint assembly / 814819A2 $499.99

28315 Alpha 1 drive shaft yoke

15
Yoke engine drive shaft

28030 Alpha 1 U-joint

16A
P/N 28030
 Heavy duty Rockwell u joints replaces part number 75832T-1 $51.99

28100 Alpha Generation 2 socket

17
P/N 28100
 Socket for yoke $79.99

28310 Alpha 1 Yoke shaft

18
P/N 28310 Yoke, 1970-1997 models / 46020-1 $79.99

28350 Alpha Generation 2 bearing retainer nut

19
P/N 28350
 Retainer nut / 816811-1 $26.99

28390 Alpha Generation 2 ring

20
P/N 28390 Upper gear-case ring $13.99

82380 OMC O-ring

21
P/N 82380
 O ring

28370 Alpha Generation 2 bearing carrier assembly

22
P/N 28370 Carrier assembly / 66081A2 $43.99

85030 Alpha 1 oil seal

23
P/N 85030
 Oil seal – for yoke $14.99

21520 Alpha 1 bearing set

24A
P/N 21520
 Roller bearing (All Ratio except 1.32), 1964-1997 models. 31-35988A2 $179.99

23280 Alpha 1 shim kit

25
P/N 23280
 Double bearing shims (6 units) 15-35980A1 $10.95

28380 Alpha 1 Spacer

26
P/N 28380 Spacer / 15-71013 Two units $9.99

28330 Alpha 1 tension washer

27
P/N 28330 Tension washer / 12-45810 $4.95

28360 Alpha Generation 2 nut

28
P/N 28360 Lock nut / 11-22339 $4.95

21731 Draining screw plug OEM 22-67892A1

29
P/N 21731 
Magnetic drain screw. Same screw is used in the lower units. $9.95

31170 Mercruiser seal gasket

30
P/N 31170
 Washer $9.99

28300 screw

31
P/N 28300 Cover screw / 10-98794 $4.95

21890 plug

32
P/N 21890 Plug / 19-47579 $4.95

21170 lock nuts

33
P/N 21170
 Lock nuts (5) 11-13439-1 $15.99

31150 Water pump gasket

34
P/N 31150
 gasket (5 units) for water cover pocket (Included in seal kit) $9.95

22440 screw

35
P/N 22440
 water pocket screw / 10-28668 $4.95

Pocket cover tube passage 12200

36
P/N 12200 pocket cover kit. Replaces 42724A3, Sierra 18-3219. $32.99

21423 Alpha 1 bushing

37
P/N 21423 Bushing / 23-32632 $20.95

38
Grommet

12202 Water Tube

39
Copper tube

22031 Alpha 1 welch plug 1.250 inch

40
P/N 22031
 welch plug (1-1/4″O.D.) 19-42682 $4.95

22032 Mercruiser pipe plug

41
P/N 22032 Pipe plug OEM 22-42861-1 plug $6.99