Maintenance Procedures – Litter
75
DRIVE SCREW AND NUT REPLACEMENT – KNEE MOTOR (CONTINUED)
Procedure:
1. Remove the knee motor (see page 76).
2. Unhook hitch pin (K) from the knee section.
3. Using a 7/16” socket and 7/16” open end wrench, remove the nut, bolt and washer (F) holding the drive
screw nut and the cam wire link to the main link (G).
4. Unplug the four wires on the knee cam switch assembly. Note their locations so they are reattached prop-
erly during re–assembly.
5. Using a 5/16” nut driver, remove the two bolts (J) holding the cam switch assembly to the motor carriage
and remove the cam switch assembly.
6. Using a 3/8” socket wrench and extension, reach under the litter and remove the four bolts holding the
motor screw assembly to the litter assembly. Lower the motor carriage assembly from under the litter.
7. Place the screw assembly on a work bench in the position shown on page 74.
8. Using a 1/8” punch and a hammer, remove the roll pin (A) at the right end of the carriage assembly.
9. Remove the washer (B) and bushing at the right end of the carriage assembly.
13. Using a 1/8” punch and a hammer, remove the roll pin (C) holding the coupler (L) on the drive screw.
14. Pull the coupler off the drive screw and remove the bearing, washer and bushing (H).
15. Remove the drive screw from the carriage.
16. Remove the drive pin and washer (D) from the left end of the drive screw.
17. Turn the drive screw to remove it from the drive screw nut (E).
18. Reverse the above steps to install the new drive screw and nut and to reattach all components to the bed.
Check bushings removed in steps 9 and 11 for wear and replace, if necessary.
NOTE
Generously apply Syntech grease to the drive screw nut when installing the new nut.
Before reinstalling the carriage assembly on the litter, manually turn the drive nut approximately half–way
down the length of the drive screw. This will allow easier realignment to the litter.
CAUTION
Assure the knee motor stops properly at both upper and lower electric limits. If it does not, refer to page 71
for “Limit Setting – Knee Motor”.
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