Grizzly G9972Z Owner's Manual page 54

4.
insert the handle of a chuck key or similar
tool in a spindle indent to keep the spindle
from rotating, then remove the outer spanner
nut (see figure 79).
5.
Loosen the inner spanner nut one full turn
counterclockwise.
Note: You may have to tap on the outboard
spindle tube as explained in Step 6 to help
unload the spindle preload and break the
spanner nut loose.
6.
place a wooden block over the outboard
end of the spindle, and hit it soundly with the
heavy dead blow hammer (see figure 80).
your goal is to slide the spindle forward just
enough to introduce spindle end-play that
you can feel by hand.
figure 80. producing detectable spindle end-
play.
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7.
place a dial indicator on the cross slide and
move the carriage toward the spindle until the
contact point of the indicator lightly touches
the spindle face and the dial reads exactly
zero (see figure 81).
figure 81. dial indicator setup.
8.
Move the carriage an additional 0.100" toward
the headstock.
9.
insert the handle of a chuck key or similar
tool in the spindle indents to keep the spindle
from rotating, then tighten the inner spanner
nut until the indicator dial needle just stops
moving and is back to exactly zero.
Note: While tightening the spanner nuts, rock
the spindle back and forth slightly to make
sure the spindle tapered roller bearings seat
properly in their races.
When the dial indicator needle stops mov-
ing, there will be no spindle end-play and no
bearing preload. it is essential that you find
this point without tightening the spanner nut
too much and inadvertently preloading the
spindle bearings.
G9972Z 11" x 26" Lathe w/Gearbox