Outboard / Outdrive repair videos / Drawings / Illustrations

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OMC 800 series outdrive service

Years 1978 to 1985

  • Click on any exploded 800 series drive diagram listed below. The 400/ 800 series video and drawing were made for the do it your self mechanics and the boating enthusiasts thinking of doing there own repairs.
  • Need to find upper-lower seal kit, impeller, water pump kit and even installation help?
  • Just need the upper / lower unit exploded view gear case diagram and or video please click on the picture listed below.

400 / 800 series
Flat rate repair cost for lower units and upper gear-cases.

400-800 Tru-Coarse steering for or upper gear case will be required in most cases.

There is a left or right handed worm gear and 1/4 moon gear in most upper cases.

Unit that do not require gears may have a steering arm attached to the exhaust housing.

If you have twin engines only one will need steeling and the other will be linked to it.

Most left hand worm gears in upper gear case are used with power steering applications or steering wheel in 2 location on the boat.

Ball gears for 400/800 upper units 1967 to 1986

There are 2 main types of ball gear and there is a way of making them interchange. The shaft that holds the ball gear and the drive gear can be changed out.

The shaft is listed under OMC used parts and is also listed on ball gear page. Bearing for both type of shafts are the same and can be changed over.

Note there is a video showing the shaft being changed over.

Ball gears made in 1967 thru 1969 for 4 cylinder unit with 5/8 or so bore can not be change over but are still in stock at time of writing.

intermediate housing
intermediate housing

Note unlike the upper gear case the press on intermediate housing ball gear can only be change by changing to newer housing and engine hub.

Most people have old ball gear welded up and grounded with new seals installed.

Tech support for all OMC outdrives
exploded view drawings

OMC outdrive parts drawing

OMC outdrive parts

OMC 400-800 stern drive upper gear-case. That is ball gear drive for outdrive years 1972 to 1985 (non press on type).

800 series lower gearcase

800 series lower gearcase