Shaft Alignment

Our engine has about 370 hours on it so I am definitely overdue for a shaft alignment. Good thing I did because it definitely needed adjustment. When checking the space between the shaft and reverse gear flanges the most you want to .010 inches. This is measured with a feeler gauge. Ours was out about .014. When checking you want to check the top bottom, starboard, and port sides of the flange. The port/starboard alignment was a bit off but the biggest problem was top to bottom.

I previously had a loose engine mount nut so that may have something to do with the alignment being out. When I tried to tighten the nut on the aft port side of the engine there was no way I could get a socket on it, pliers or wrench. So, I made my own tool I took a 30MM combination wrench and cut it down so it would clear the raw water strainer. It is a little less that 8 inches long. I also cut two little notches in the end which I will explain in a minute. Because I was unable to get any good leverage on it I utilized a small steel pipe and a baby sledge hammer. It functions like a poor man's impact wrench. One places the pipe in the groove of the cut off wrench and taps on the other end with the hammer. It works very well both for tightening and loosening those large nuts.

The measurement is taken at the red vertical line in the above picture. It is the space between the bronze colored flange and the silver looking one. Of course that bronze color has turned to green with a little salt water on it. The red arrow points to one of the bolts that need to be loosened.

So once the flanges are loose and you measure the distance between them you either raise or lower the engine to tighten the gaps. I just raised the back of the engine to get the clearances closer. I now have about .005 to .007 gap. I could not figure out the side to side adjustment so I just left it alone at this time. After calling the factory I learned that the side to side adjustment is done by loosening the two bolt thats go in to the stringer and using a crowbar to shft the engine sideways. That will be attempted at the next shaft alignment check. Right now everything is within spec.

So here is the acid test. Before I did the alignment I was unable to turn the shaft by hand. I had to use a screwdriver on the flange bolt to get enough leverage to turn the shaft. After alignment I can easily turn the shaft by hand! Maybe I picked up another mpg, who knows.



RangerTug 31CB