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OMC Parts Drawing *Cobra *Mercruiser *Alpha SEI Outdrives

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  • Alpha one / Gen 2 parts drawing
Mercruiser Alpha 1 and Gen 2 tech drawing

Updated May 10 2026

  • Upper and lower gear case drawings (1967 – 1983)
  • Alpha One Gen 1 (1984 – 1990) and Gen 2 (1991 – up) drawing
  • Links to a complete list of components with photos and OEM numbers
  • Bell housing and gimbal housing break down

Mercruiser Tech Drawings

Click Photo for Components

Lower Units

Mercruiser Tech Drawings

Mercruiser Alpha 1 lower unit parts drawing

Mercruiser  lower unit

Alpha one generation one models

1970 – 1990 models
serial numbers 2791957 – 0D 469858

Mercruiser Tech Drawings

Alpha One Gen 2 Lower Unit

 
1991 – up models

serial numbers 0D 469859 – up
Mercruiser Tech Drawings

Upper Gearcase

Alpha 1 upper gear case For MC-1, R, MR and Generation 1

1970 – 1990 models, serial numbers 2791957 – 0D 469858

OMC outdrive repair, OMC parts, SEI sterndrives, Mercruiser outdrives, Johnson water pumps

Alpha One Gen 2 upper unit

1991 –  Present models, serial numbers
0D 469859 and up

T.C.Electronics larger drawing upper gear case

 

Click Photo for Larger View

Bell Housing / Gimbal Housing

Mercruiser Tech Drawings

Bell Housing Layout

Years 1970 to 1990 models

serial numbers
2791957 – 0D 469858

Mercruiser Tech Drawings

Alpha 1 generation 2 bell housing layout

Bell housing

Generation 2

1991 – present models
serial numbers 0D 469859 and up

Alpha One Generation 2 Bell housing with transom service parts and install video.

Mercruiser Tech Drawings

Gen 2 Transom

Gimbal housing for Mercruiser, Alpha One and Alpha One generation 2


R, MR, Alpha 1 and Generation 2 gimbal housing parts drawing

  1. P/N 85420 Oil Seal OEM 26 – 54925
  2. P/N 85440 Oil Seal 26 – 32911
  3. P/N 21906 Gimbal Bearing 30 – 879194 A01
  4. P/N 85910 oil seal
  5. P/N 21790 clamp
  6. P/N 89080 Bellow 74639 A2
  7. P/N 21791 Clamp 54 – 31766
  8. P/N 21970 Trim parts kit 98825 A4
  9. P/N 32500 Gasket
  10. P/N 05009 Lockwasher
  11. P/N 22440 Screw
  12. P/N 86712 Transom Seal
    (MC-1/R/MR/Alpha One) 65533 A1
  13. P/N 86711 Transom
    Seal Alpha One generation 2 OEM 243713
  14. P/N 82460 Seal 41802
  15. P/N 12700 Anode 5598909
  16. P/N 30355 Gasket 12 – 56085
  17. P/N 12713 Anode 821631 01
  18. P/N 85656 Seal 012077
  19. P/N 33000 Gasket 44108 -1
  20. P/N 22147 Cotter Pin 18 –  54929
  21. P/N 01071 Clamp
  22. P/N 47110 Water Hose 3/4″ O.D. 32 – 41725 – 33
  23. P/N47120 Water Hose 5/8″0.D. 32 – 32461
  24. P/N 21164
    Locknut 11 – 25599    
  25. P/N 12967
    Plug 22 – 88847
  26. P/N 16005 Plug Kit 22 – 88847 A1
  27. P/N 12713 Aluminum Anode Kit 821631 Q1
  28. P/N 21180 Locknut 11 – 826711 – 9

Exhaust manifolds and risers

Exhaust manifold kit

Exhaust manifold applications
58232
GLM Marine after market Mercruiser years 1983 to 2001 exhaust kit

P/N 58231 / 58232 

Complete Mercruiser GM V8 small block Chevy exhaust set with 3 inch or 4 inch riser.

GLM Marine after market Mercruiser parts:

  1. P/N 51230 V8 small block chevy cast iron exhaust assembly / 860246 Q11 x 2
  2. P/N 51110 / 98504 A3 or 51140 / 807988 A2 V8 small block
  3. Chevy exhaust elbow – riser (3 inch or 4 inch) x 2
  4. P/N 31100 Gasket / 27 – 33395 x 2
  5. P/N 30240 Gasket / 27 – 863724 x 2
  6. P/N 13991 90 degree hose fitting / 22 – 806926 x 2
  7. P/N 13992 Drain plug / 22 – 806608 A02 x 2
  8. P/N 80140 O-ring for plug / 25 – 45253 x 2
  9. P/N 22391 Stud / 16 – 49545 x 8
  10. P/N 21248 Locknut / 11 – 46335 x 8

GLM Marine after market
Mercruiser exhaust parts:

305 V8 200, 1985 – 1987
(S/N 6899058 – 0B 774444)

228, 1983 – 1995
 (S/N 6218462 – 0F 600999)

230, 1985 – 1987
 (S/N 6899269 – 0B 773739)
230 MEI, 1981 – 1987
 (S/N 5907058 – 0B 788151)

5.0L, 1988 – 1995
 (S/N 0B 774445 – 0F 600999)
5.0L EFI Gen +, 1998 – 2001, (S/N 0L 012052 – Up)

5.0L LX, 1988 – 1995 (S/N 0B 773740 – 0F 600999)

898, 1983 – 1984 (S/N 6218462 – 6899057)

260, 1983 – 1987 (S/N 6218462 – 0B 773304)

260 MEI, 1981 – 1987 (S/N 5907058 – 0F 024999)

300, 1985 – 1986 (S/N 6668677 – 0B 430367)

320 EFI 1987 – 1989 (S/N 0A 543604 – 0C 622418)

350 MAG Alpha 1986 – 1987
(S/N 0A 635178 – 0K 999999)

up
(S/N 0M 300000 – up)

5.7 years 1988 – 2001 (S/N 6218462 up

5.7 Liter MIE Gen +, 1998 – 2001 (S/N 0L 002003 – up)

5.7L Ski, years 1985 – 2001 (S/N 0A 338533 – up) 5.7L LX

350 / EFI / Bravo, 1996 – 1997
(S/N 0F 601000 – 0K 999999)

377 Scorpion MCM, 2001 – 2001
(S/N 0L 416146 – up)
377 Scorpion Ski, 1997 – 1998
(S/N 0K 000656 – up)

MX 6.2L MPI 377 / Horizon, 2000 – 2001 (S/N 0L 68003 – up)

$599 US

$791 CDN