Saturday, June 25, 2016

1973 Johnson 9.5: Drive shaft Stuck in the Crankcase



During a routine water impeller replacement, I discovered the above problem when the driveshaft remained up in the crankcase instead of dropping down with the lower unit.  After quick attempts to pull it free failed, I did some research online and in the manuals.  The only suggestion I could find was putting penetrating oil down the stuck driveshaft and attaching vice grips to the shaft, then hanging the whole works from the ceiling with a chain on the vice grips to pull it free.  Silly as this sounds, I tried it for two weeks, to no avail.  All I accomplished was saturating the points and coils in oil, but that is another story.

Here is what I did to get the driveshaft out:

First, I disassembled the motor down to access the point where the driveshaft enters the crankcase.  Make sure you wear safety glasses and gloves for this.  It is a big job, but critical as you need to get at the O ring around the driveshaft buried in there that is keeping the penetrating oil from getting to the splines of the driveshaft.  I made a small tool out of hardened brass to fit in the tight void around the driveshaft and cut up the O ring. 
I then let it sit a few more days, but It still did not come free for me, but may in other cases.

I then made the following Jig:  


You will need,

1. Three pieces of Oak, Hickory or a hard wood of the following dimensions: all with a 3/4 hole in the center for the driveshaft to fit through:
  • a. 27 1/2 x 4 1/2 x 1 1/2
  • b. 11 x 3 1/2 x 3/4
  • c. 18 x 3 3/4 x 1 1/2 with 1/4 x 1 steel attached to the bottom for extra support.




2. A piece of pine plywood cut to at lease one inch beyond the edge of the engine block with a 3/4 hole drilled in it for the driveshaft to fit through.  This piece needs to have a 2 1/4 round x 1/4 deep chamfer cut around the driveshaft hole to clear the pilot ring on the bottom of the block.




3.  3 big Vice Grips
4. 2 hydraulic jacks

Set up the jig as seen in the photos.  You can try to save your driveshaft by wrapping it in a towel, or attaching the vice grips in an area not vital to the operation away from any seals or the impeller, etc.
Once the shaft is free, clean up the driveshaft hole in the crankcase with oil and a wire brush, cotton swabs, etc to get all debris out.  The reason mine was stuck is, apparently whomever did the impeller service last had failed to properly grease the upper splines with the reccomended grease.  Please remember to do this upon reassembly to save yourself a lot of grief next time around.  Good luck.


 











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