Normal *installed* clearance is 0.003-0.005" per inch of shaft diameter.
The *installed* requirement includes the 'press fit' in the housing
...... which means that the bearing inside diameter gets smaller when
you *press* it into the housing.

So when ordering a new bearing you must measure (with micrometer) the
housing journal inside diameter to ± 0.001 AND the shaft diameter.
to±0.001

A perfectly sized cutless installed to a shaft/engine that is perfectly
aligned will last many many years.


article .com,
wrote:

Posting about shaft packing got me thinkin about cutless bearings and
when it is time to replace them. My shaft wiggles just a little bit
(almost no play) in the bearing and it is 24 yrs old. Last time I was
in a boat yard, I went around wiggling shafts in cutless bearings and
found a huge variation in bearing "play". Some were tighter than mine
but most were looser. One was so loose it would THUNK from side to
side. What is normal and what is bad?