Front motor adjustment

Gimbal bearing p.n.

alignment tool
p.n. 91-57797A3

Engine Coupler    See Coupler chart  for details.

The down and dirty of this job is to verify if the engine and drive shaft are in alignment. Before you start this job as a new mechanic or Do-it- yourselfer, I need to warn you that as simple as it looks, I've seen too many of these done incorrectly and the out come is an engine pull. So, if your ready to go ......

Warning: The tool that is used can be rented from some tool rental places but be careful because there are now two tools on the market. The new style tool will work on the older motors but the old style tool will not align new style motors properly.  See tool bulletin.

The first step is to get ready to remove the drive by putting the unit in forward gear, (reverse gear for counter rotation) and removing the trim pin and nuts that connect the drive to the trim system. Then either support the drive from above or place blocks under the sterndrive so that the u-joint driveshaft is inline with the crankshaft of the motor and not cocked up or down, or side to side. Place 3ft. long 2x6 boards on the ground so you can slide the drive off and on without much lifting. At this point you need to:

    Tip #1) Get the manual and do it like they tell you to do it.

    Tip #2)  Always have someone check it who has done it before.

    Tip #3)  Look carefully at the spline and the coupler for wear. If  the grease dried up and the spline ran dry, have a professional look at it to see if you should reassemble. Usually the coupler is the first to wear when they run dry. If the spline teeth in the coupler look "pointy" or half of the spline tooth is worn away, replace the coupler.

   Tip#31/2) If you have good alignment  but the couple has dry teeth upon inspection, tap the engine over 180o, to see if the coupler is warped and or warbling and then recheck the alignment. If the alignment has changed after cranking the motor 180o, the coupler is shot.

    Tip #4)  Always use M/C Spline grease and no other product on the splines.

    Tip #5) This is a good time to hand grease the gimbal bearing. Spin it with your fingers, before you grease it. If it feels rough or the cage feels  loose, replace it , don't waste your time greasing it. ( the same for the U-joints) If all is well spin the bearing while greasing to fill more completely.

Note: Do not use spline grease in the gimbal or u-joint bearings.

  *Are there signs of water and or rust in the bellows? If so fix that problem , before reassembly.
   *Are there rust stains on or around the shift cable pocket? Look for and fix that leak, before you need a new shift cable too. ( don't forget to check for a loose core plug under the upper stern drive decal....)
  * Do all  your hoses behind the bell housing look good? Especially check the water hose between the bell housing and the transom assembly for cracks.
*Clean the areas your going to glue the rubber seals and o-rings into, with a good cleaner and install new seals and o-rings and let the glue dry thoroughly, before drive installation. Always install new o-rings and gaskets. On sterndrives that require a sterndrive gasket, NEVER install two sterndrive gaskets or glue them in place., in an attempt to stop leaking. If you rip a sterndrive gasket while installing the drive, get a new one.

   Tip #6) Even if you didn't need to re-adjust the alignment, re-torque the motor mounts. Check and reset the locking washers on the motor mounts when your done doing the adjustment.

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