OMC Parts / OMC Cobra Stern Drive Tech Drawings

OMC Cobra shimming techniques newsletter 102

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22-962-Gearcase-kit-ratio-21-16.jpg
OMC Cobra upper gear case components 1985 to 1995

OMC Cobra parts for repair and shimming of upper gear case yoke-water pump shaft assembly

  • Water pump shaft bearing removal is best removed by grinding one side of cone bearing until a line break can be seen on the race. Note the water pump shaft must be protected with a cover of some type in case grinder slips.

 

  • Aftermarket omc cobra shimming parts with plastic shim sizes .007, .009 and .011. comes in a kit. T.C. Marine uses a standard shimming size of .020 between the front yoke bearing carrier # 27920 and the case, see picture illustration.

tool_124.jpg
tools

  • Stainless steel shims sizes of .005 # 23372, .007 # 23373 and .010 # 23374 on drawing are then placed in back of rear bearing cup untill 5 to 8 torque lbs specification is made. In the marine trade this is called bearing preload.

This tool can be purchased at snap on tools
tools_2.jpg
Instead of grinding this tool and heat will remove small bearing

  • Gasket sealant and retaining compounds are required, Loctite aviation gasket sealant ( liquid type ) # 30517 is used with all o-rings
  • Loctite 680 # p/n #68015 retaining compound for small yoke shaft bearing cup and outside seals.

In a pinch a pipe wrench will work
tool_1.jpg
This is an OMC Tool but a # 4 bearing nut wrench can be used

  • Yoke water pump shaft # 28320 must be shimmed first with out the pinion gear installed, so torque value can be adjusted with out lower pinion gear drag.
  • Note failure to replace # 22525 centering cone may result in driven gear bearing out of round on yoke drive shaft.
  • U-joint nut # 28470 can be reused if blue loctite is used with the nut.
  • Oil seal # 86530 and oil seal # 86610 should be used with loctite 680 after bearing carrier seal area is sanded clean or wire brushed.

  • This page will forward to our tech service web site around Jan 30th 2010, until this time please contact tech service department for questions concerning your repairs.

  • OMC Cobra and king cobra stern drive repair manual by Seloc will give step by step procedures to help boating enthusiasts performing their own work. They are sold by Wal-Mart on-line or Wal-Mart stores.

Repair parts that may be needed for OMC Cobra upper gear case are listed below
  • # 15 #22525 Centering cone $28.79
  • # 16 #28470 U-joint nut $15.79
  • # 5 #28460 Pinion nut $23.79
  • # 34 #27800 Pinion / bearing carrier $77.79
  • # 3-4-14-17-2227 Bearing set $129.79
  • # 7-12-13-18-19-20-21-22-26-28-29-37-53
  • Above parts in # 87654 Seal kit $31.79
  • # 45 #23366 Plastic shim kit $14.79
  • # 52 #23372 .007 Shim stainless steel $8.79
  • # 52 #23373 .010 Shim stainless steel $4.79
  • # 52 #23374 .012 Shim stainless steel $4.79
  • # 52 #23372 .015 Shim stainless steel $4.79
  • # 30517 Aviation gasket $12.79
  • 60921 Loctite $19.79
  • #11 #28320 Yoke-water pump shaft $226.79

Total Repair parts cost $605.56