Mercruiser Alpha 1 parts drawing *Lower unit 1-34

GLM Marine aftermarket lower gearcase stern drive parts.
Exploded view outdrive drawings.

Last updated on 12/08/2023, 01:17:46

  • All GLM products are brand new completely compatible and interchangeable with Mercruiser Alpha One parts. GLM has committed to producing high quality and cost effective aftermarket parts for the past two decades
  • Upper gear case exploded view Alpha One drawings click here

Alpha one lower gear case layout drawing

Picture

Description

87510 seal kit

A
P/N 87510
 Seal kit (lower unit) gear-case 26-33144A2 $44.99

25125 seals gears bearings shims 13-21

B
P/N 25125
 Seal, bearing and gear set 43-803091T1 $699.99

25120 Alpha seal kit shims bearings

C
P/N 25120 
Seal and bearing set with P/N 21570 upper bearing $267.99

12120 water pump

D
P/N 12120
 Water pump set $42.99

18000 Alpha 1 lower case only

1
P/N 18000
 Lower gear housing (Case only) call for price and availability

Alpha 1 lower unit complete

P/N SE109 SEI Marine aftermarket lower unit replacement outdrive complete assembly years 1972 to 1990 $1125.99

12410 housing

2
P/N 12410 Water pump housing $29.95

12810 cup

3
P/N 12810
 Cup $5.95

89840 Alpha 1 Water pump impeller

4
P/N 89840
 Water pump impeller $16.99

23200 retainer

5
P/N 
Retainer for drive shaft bearing 824519-1 $4.95

12833 screw

6
P/N 12833
 Screw for wear plate cover 10-96411 $4.95

21180 lock nuts

7
P/N 21180
 Lock nuts (5) 11-13438 $9.95

12830 seal

8
P/N 12830 Seal

12820 guide tube

9
P/N 12820
 Tube guide

81160 o ring for drive shaft

10
P/N 81160 o ring (5)

21190 lock nuts

11
P/N 21190 
Lock nuts (5) 11-13436 $9.95

21720 washers

12
P/N 21720 Washer set (3) 12-36001 $4.95

11070 Impeller key

13
P/N 11070
 Impeller keys (1) 28-56654 $9.95

31020 Alpha 1 water pump to wear plate gasket

14
P/N 31020
 Gasket

12510 impeller wear plate

15
P/N 12510 Wear plate

16
P/N 31010 Gasket for wear plate

12320 base

17
P/N 12320
 Water pump base

85040 oil seal

18
P/N 85040
 Oil seal

85070 Alpha 1 oil seal

19
P/N 85070
 Oil seal $12.99

81390 O-rings

20
P/N 81390 o ring

82270 Alpha 1 O-ring

20B
P/N 82270
 Water pump o ring

21580 bearing

22
P/N 21580
 Tapered roller bearing for drive shaft MR/Alpha One/Gen 2 OEM 31-36387A1 $46.99

23210 drive shaft bearing shim set

23
P/N 23210 
Shims 15-42637A1 $16.95

21800 washers

24
P/N 21800
 Washer set (5) 12-29395 $4.95

30010 outdrive gasket

25
30010
 Washer gaskets OEM# 12-31266 $4.95

85581 oil seal

26
P/N 85581
 Oil Seal

21010 bushing assembly

27
P/N 21010
 Shift bushing assembly

81180 OMC O-rings

28
P/N 81180
 O-Ring

32790 washers

29
P/N 32790
 Washer set (10) 12-27880 $4.95

21132 outdrive clip

30
P/N 21132
 Clip 18-20233

21030 lower shift shaft

31
P/N 21030
 Shift shaft 77481-1 $43.99

85140 oil passage seal

32
P/N 85140
 Oil passage seal (5) 26-45577-1 $9.95

21731 draining screw set

33
P/N 21731
 Oil plug drain screw magnetic 22-67892A1 $9.99

31170 Alpha 1 gasket for housing drain screw

34 # 31170 Washer

Alpha 1 lower gear-case exploded view parts drawing
Parts 35 – 55
56 – 77