Chapter Five – Maintenance Procedures – Litter
108
5.5 HEAD SECTION (CONTINUED)
DRIVE SCREW AND BALL NUT REPLACEMENT – HEAD MOTOR (CONTINUED)
7. Slide the cam and retention wire as far toward the foot end of the bed as possible to allow proper clearance
for removal of the drive screw.
8. Remove the hinge pin from the Fowler and main link.
9. To prevent the ball nut from coming off the drive screw, cable tie both ends of the ball nut to the drive screw.
10. Pull the drive screw toward the foot of the bed and remove the head end of the drive screw and ball nut
assembly from the support (D). Push the drive screw toward the head end of the bed and remove the foot
end of the screw from the glide bushing support (E).
NOTE
Do not allow the ball nut assembly to come off the drive screw. The ball nut will be shipped attached to the
drive screw and retained in position during shipment. Remove the restraining straps before installing the drive
screw and nut.
11. Remove the thrust washers and bearing from the head end of the drive screw and set them aside.
12. Using two 7/16” open end wrenches, remove the bolt, nut and bushings (C) supporting the ball nut assembly
on the Fowler link.
13. Reverse the above steps to install the replacement drive screw and ball nut assembly.
NOTE
Apply grease to all bearing areas.
CAUTION
Assure the head motor stops properly at both upper and lower electric limits. If it does not, refer to page 102
for ”Limit Setting – Head Motor”.
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