Stairmaster Stratus Systems Owner's Manual page 59

PARTS REMOVAL AND REPLACEMENT
4. Loosen and remove the bottom bracket jam nut located on the left
side of the crank (see Figure 23). This nut has reverse threads; loosen
it by turning it clockwise.
5. Remove the round, metal crank shield from the left side of the crank.
6. Remove the bearing clamps by loosening the allen bolts from the left
side clamp.
7. The left bearing nut assembly can be removed from the crank with a
15-mm cone wrench. This nut has reverse threads; loosen and
remove it by turning it clockwise.
8. Slide the crank out of the frame to the right.
9. The right bearing nut assembly can be removed from the crank with a
32-mm cone wrench. The right bearing nut assembly also holds the
chain ring in place on the crank. If the chain ring is damaged, replace
it now.
10. Inspect the bearings for smoothness of operation. Replace the
bearings if necessary.
11. Ensure that the right bearing nut assembly is tight against the
chain ring before reinstalling the crank into the frame. The outside
edge of the bearing nut assembly should be flush with the bottom
bracket when the crank is installed.
12. Install the left bearing nut assembly onto the crank and tighten it so
the outside edge of the bearing nut assembly is flush with the bottom
bracket (see Figure 23). Do not overtighten the nut; the crank should
spin freely.
13. Install both bearing clamps and tighten the allen bolts. Do not
overtighten the allen bolts; the crank should spin freely.
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