IBM 6400 series Maintenance Manual page 386

The paper stacker assembly mounts to the rear upper frame
cross-member and to the cabinet floor. It is a snug fit. During
installation, take care to avoid scratching painted surfaces or damaging
the stacker.
9. Position the elevator assembly at the bottom of the vertical rails. (See
Figure 68a.)
10. Insert the vertical rails inside and under the upper frame cross-member,
then slowly swing the base of the stacker assembly into the cabinet. (See
Figure 68a.)
11. Work the stacker base rearward and engage the upper brackets of the
vertical rails under the upper frame cross-member. (See Figure 68b.)
12. Align the holes in the vertical rail brackets with the holes in the upper
frame cross-member.
386
ATTENTION
Power Stacker