3-53. PROPELLER SHAFTS - MAINTENANCE INSTRUCTIONS (Continued).
engine. If threaded holes are provided in each of the engine mounts, jacking
screws can be used in them. The engine can be raised by screwing down, or
lowered by backing off the desired amount. Steel plates must be inserted under the
jacking screws so that the jacking screws will not damage the engine bed. Lifting
can also be accomplished by the use of properly placed jacks. Adjustable shims
also are available and can simplify the whole problem, particularly for future
(1) It will also be necessary to move the engine and gear from one side or the
other on bed to obtain horizontal alignment. This can be done with a jack placed
horizontally between the engine and the foundation. At the same time, a straight
edge is laid across the edges of the flanges at the top and side to check the
parallel alignment of the coupling edges.
(2) As the engine and marine gear then comes into its aligned position, it will be
possible to match the male and female halves of the output flange and propeller
coupling, and prepare for bolting together. Care should be taken not to burr or mar
this connection because the fit is very critical. Place a 0.002 inch (0.005 cm) feeler
gauge between the flanges of the coupling. The feeler gauge is moved (slid)
completely around the coupling.