From what I see of your drawing, the fitting your discribe forward of the
prop is a standard strut.. I doubt that your strut installation is made to
take the full thrust of the propellor..

I agree with Matt.
Conventions would have the thrust bearing in the hydrolic pump and only a
cutlass bearing in the strut.

I suspect someone has tried to 'Improve' the installation.. Or the hydraulic
motor has a bad thrust bearing.

If in doubt, contact the manufacture of the hydraulic motor and determine if
the the motor has a thrust bearing in it.. If so then you need to verify
that it is in good condition and leave the one you found out of the
installation..

Or there is another possibility, that the original builders hydraulic motor
went bad and some one put a conventional/industrial replacement in it's
place. In this instance the industrial motor most likely wouldn't have a
thrust bearing.

Just my speculation, FWIW.

Steve
s/v Good Intentions