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Mercruiser outdrive parts *SEI lower unit *Alpha 1 repairs

GLM Marine aftermarket Mercruiser parts
Alpha One outdrive
SEI Replacement Mercruiser outdrives,
repairs and rebuilds

Click Mercruiser parts image below for
GLM Marine exploded view diagram

Mercruiser Alpha 1 lower unit parts drawing
 Lower gearcase
upper gearcase parts drawing

Upper gearcase technical drawings

Mercruiser gimbal housing

 Gimbal housing drawings

Mercruiser bell housing parts layout

Mercruiser bell housing layout

Trim cylinder parts and hoses 1983 to 1990

Trim cylinder and hoses 1983 to 1990

Trim cylinder and parts
Trim cylinder parts repair kit
SEI lower units

Lower Units

Aftermarket upper gearcases

Upper gearcases

Transom service kit
Transom Kits
Seal Kits
GLM Marine or Sierra
Alpha one seal kits
Water pump kits
Water pump kits
Exploded View Parts Drawings
Exploded View
Parts Drawings
Outdrive Shift Cable

Shift Cables

11215 Mercruiser V8 upper gearcase service kit

11215 Mercruiser V8 upper gearcase service kit

Outdrive Upper-Lower Gearcase Bearings
Mercury marine bearings
exhaust manifold kit
Exhaust manifold kit
Exhaust manifold

V8 350 Exhaust manifold

Mercruiser Alpha 1 Upper gearcase service tools

Upper gearcase service tools

Outdrive Tools

Outdrive tools

Mercruiser Alpha One Drive Shaft
Drive shafts
Trim Cylinder Hoses

Trim Cylinder Hoses

Mercruiser outdrive shift cable and parts

Outdrive shift cable and parts

Mercruiser Repair Costs
Repair Costs
Water separating fuel filter kit

Water separating fuel filter kit

24980 Fuel filter kit

24980 Fuel filter kit

Anode Kits

Anode Kits

32170 Exhaust Manifold Gaskets

Alpha 1 or Generation 2 for
4bbl and 2bbl
carburetor kit

21731 Drain plug

21731 Drain plug

40155 In-line fuel filter with .312 inch hose

Inline fuel filter

Mercury Water Pump

Mercury Marine outboard water pump

Gimbal bearing

Gimbal bearing

90065 Prop wrench kit

90065 Prop wrench kit

Mercruiser engine carburetor kit
Engine carburetor kit
Mercruiser Alpha 1 Gen 2 engine coupler

Mercruiser engine coupler

Mercruiser engine rebuild kits
Mercruiser engine rebuild kits

Mercruiser Alpha One Generation  2 upper parts 1991 - 1997

Mercruiser Alpha One Gen 2 upper

Mercruiser Alpha One generation 2 lower unit parts

Mercruiser Alpha 1 Generation 2 lower unit

What,s New


  • SEI Marine products including aftermarket Mercruiser Alpha One and generation 2 outdrive boats
  • Have a new aftermarket OMC Cobra and 800 lower unit gear case
  • Seloc manuals for Mercury marine inboard outboard sterndrive, Johnson/Evinrude and Mercury marine outboard motors
  • Upper - lower units gear-case are OEM outdrive boat replacement for both Mercury Marine and OMC Johnson/Evinrude
  • We carry all inboard-outboard upper gear case gear ratios for 4 cylinder, 6 cylinder and V8 boat engine up to 300 horse power
  • Upper unit can come with and without the 9 9/16” long yoke on the upper drive shaft.
  • Our complete drive shipped in two pieces and will require an installation kit the includes nut kit, mounting gasket and mounting bolts. Other accessories like sterndrives anodes and shift cables need to be ordered separate. Mercury marine outboard manuals.

New Repair Tools

  • Mercruiser marine repair tools including P/N Keen 75057 3" Scotch-Brite polishing wheel. Used for the inside upper gearcase bearing area on Alpha 1 and Alpha One Generation 2 outdrives. Scotch-Brite area sterndrive must be cleaned with lacquer thinner to remove small particles and allows bearing, yoke and gear assembly to side in to upper gearcase. Note polishing and cleaning wheel will require the use of any 1/4 " or larger electric drill and should be use on the sterndrive bearing area at highest rpm setting.
  • Piston ring installer is used to line up a bearing during bearing and yoke installation
  • 3/16 inch retainer wrench thats painted black. Spanner nut wrench and bearing retainer wrench installs and removes drive shaft bearing retainer on MC-1 / R / MR / Alpha 1 / Alpha 1 generation 2, Blackhawk, and Bravo OEM: 91-17256
  • Mercruiser sterndrive universal puller plate. Pulls gears and bearings OEM: 91-37241
  • Seloc manuals for Alpha one or generation 2 at this time we do not carry the original mercury outboard or Alpha sterndrive manuals, how ever they can access the 1 year down loaded online.

Complete rebuild Mercruiser sterndrive package for 1.50 / 1.47 gear ratio for V8 350 mag engines models 20 / 22 tooth count for years 1974 to 1990 engine serial number (3856268-0D469858)
Sterndrive parts included:

  • GLM Marine part number 11210 Gear set
  • GLM part number 87500 Oil seal kit
  • GLM part number 39590 Mounting gasket and o-ring parts
  • GLM part number 21560 Bearing, 21520 Bearing and 21510 Bearing
  • GLM part number 23260 Shim kit, 23270 Shim kit and 23280 Shim kit set


Our standard shipping rate is for FedEx 2 day express to the United States and Central Canada for 5 lbs or less. Overnight express, and ground shipping is also available. We also ship to all of Europe, the UK, Australia and New Zealand.

Mercruiser Parts

We stock new and used Mercruiser outdrive parts. Alpha 1 or generation 2 (all years) components. There is an on line schematic to locate gear sets, water pumps and upper-lower gearcase bearings. Exploded view drawings show seal kit parts included, engine gasket sets and Alpha 1 or generation 2 exhaust manifold kits and more. Mercury marine outboard manuals.

We offers repairs to upper gear housing units and lower unit gear case units. New Sterndrive We carry new replacement stern drive units, complete with a 2 year warranty. No core charge required.

Manifold & Elbow Assembly Note
  • Make sure all gasket surfaces are clean, free of grease and install the new engine water hose fittings in manifolds. Tighten securely and position opening towards front of engine, facing slightly outboard (approx. 10-15 degrees).
  • Install the new exhaust manifolds with the new gaskets. Torque the screws to 33 ft.lbs. (45Nm) for cast iron manifolds (see Fig. 2).
  • Install the starboard water hose and tighten hose clamp securely.
  • Route the port water hose beneath the engines power steering pump and install on hose fitting. Tighten hose clamp securely (see Fig. 3).
  • Ensure the water shutters are in good condition and installed in the lower Y-pipe.
  • Install plugs in new exhaust elbows tighten securely and apply sealant to the threads of the elbow to manifold screws.
  • Install the elbows to the manifolds using the new gaskets and screws (see Fig. 4). Torque the screws to 33 ft.lbs. (45Nm) for cast iron elbows.
    Connect the engine side intermediate elbows to the elbows with the tubes and clamps included in the kit. Tighten clamps securely.

GLM aftermarket V8 manifolds

  • Separating exhaust Gas Pulses All V8 engines have a firing order that fires two cylinders within 90 degrees of each other on the same bank of cylinders.
    With a firing order of 1-8-4-3-6-5-7-2, we have #8 and #4 firing on the starboard side of the engine within 90 degrees of crankshaft rotation.
    On the port side, we have #5 and #7 firing within 90 degrees of crankshaft rotation of each other.
  • Of course, this also means that the gases for these cylinders immediately discharge into the manifold one after the other.
    At this point, when the two cylinders fill the manifold in immediate succession, the manifold becomes overwhelmed with gases, creating excessive back pressure.
    In fact, excessive back-pressure from an over whelmed exhaust system will not only keep spent gases from leaving the cylinder head exhaust port, but in certain ports,gases from adjacent cylinders may find their way back in.
  • The solution is to isolate each gas pulse for as long as possible in the exhaust manifold.
    There are aftermarket manifold manufacturers that go to great lengths to isolate each exhaust pulse the full length of the manifold, and there are some that barely address the problem at all.
    Choosing a high performance manifold that isolates each runner is the key to building horsepower with the exhaust system.

    Shipping Locations

    Monrovia, California 91016 USA.
    Toronto, Ontario M1R 5G2 Canada

Authorized GLM dealer

Technical Support by video

Technical support available from Wayne at our Toronto, Canada location
Search on Google for YouTube videos by Wayne Coll or T.C.Electronics/Marine
there is about 72 boat repair video in total as of 2019 there is no charge to view

Sample of sterndrive videos

  1. Mercruiser Outdrive Bellow & Shift Cable Repairs 647,893 views
  2. Water pump removal and repair video 320,210 views
  3. How do I remove my Alpha 1 gen 2 lower unit 76,349 views

Payment Methods

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