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Troubleshooting worn out OMC ball gears

Excessive ball gear wear from poor instillation and driving techniques

  • Poor driving habits
  • Operating with outdrive in up position
  • Intermediate housing guide pins seating out
  • Guide pin lining up or bent
  • Clutch plate slipping in reverse
  • Marking gears when doing repair work
  • Loose or worn bearing or housing
  • Ball gear drive shaft shimming or installation
  • Lower unit bearing resistance

Broken bearing removed

Broken bearing removed

Add 680 Loctite to taper of shafts

Add 680 Loctite to taper of shafts

Clean water seal area for retainer compound used later

Clean water seal area for retainer compound used later

Metal taper must be polished out

Metal taper must be polished out

Remove old build up
Remove old build up

By author Trish Dougherty

OMC Stringer 400 and 800 outdrives need to be in the fully downward position before starting or driving the boat. If you drive with outdrive up only one or two teeth will come in contact with teeth pulling all 235 hp. of torque on them. The second problem is that a new wear pattern will start at a rate of up to 20 time normal wear.

Here the thing most OMC out-dive boat operator's understand there boat needs to be driven with the outdrive down, but what they don't no is that it is in the up position to start with.

How is this possible?, very easy you place the drive all the way down when you get in the boat, then you go into reverse at the dock. To much power or poor clutch plate will allow the stern drive to slip upward of 1/2 to 3 inches. Unit will then slip into proper position when enough torque is applied in forward, however during this transition time there can be large amount of ball gear wear taking place. The fix is easy all ways back out at ideal speed and press the tilt down ward each time you shift into forward gear.

Check to see if the outdrive will seat out on the guide pins if unit will not loosen of on the tilt gear 3 bolts or check if tilt gear support is bent. In some cases you can shim gear in others the upper gear-case will need to be replaced.

Clutch plates may be slipping and need replaced or adjustment in some units.

Mark the position of the ball gear teeth when removing outdrive to do repair work so wear pattern will remain the same.

Poor wear pattern

Loose worn bearing and poor upper gearcase rear bearing shimming or spun bearing in outdrive will give you large amount of ball gear wear. This happen just before the upper gear set breaks in most cases.

Standard puller for timken races

Standard puller for timken races