Replacing The Pinion Shaft - Cardiac Science ST 55 Service Manual

Repair/Replacement and Calibration

Replacing the Pinion Shaft

Remove the deck assembly, (see
1.
page 5-29) then remove the rack gear as previously described for jammed rack gears on
page 5-23.
Restore power to the treadmill, then use the grade motor to turn the pinion shaft until
2.
the setscrew on the sprocket is visible.
Grade Motor
Turn off the power and the treadmill circuit breaker, then unplug the treadmill.
3.
Loosen the setscrews from the grade sprocket.
4.
Remove the grade motor chain as described on
5.
Remove the handrail support bracket on the right side.
6.
Slide out the pinion shaft.
7.
Slide the new pinion shaft into place: be sure to reinstall the grade sprocket and key
8.
while installing the pinion shaft.
Replace the handrail support bracket.
9.
Use a straight edge to align the grade sprocket and grade motor sprocket, then tighten
10.
the setscrew.
Replace the grade motor chain as previously described.
11.
Reassemble the deck assembly and poly-V drive belt.
12.
Reassemble the rack gear.
13.
Calibrate the grade potentiometer (see
14.
Test the treadmill grade. Verify that:
15.
It operates over the full range of 0-25%.
a.
There is no binding when it moves up or down.
b.
The grade motor chain is aligned correctly. A popping sound in the chain indicates
c.
misalignment.
70-00298-01 A
5-24
Removing the Deck Assembly from Headframe
Chain
Calibration Procedures
Pinion Shaft
page 5-18.
on page 5-37).
TM 55/65 Treadmill 4.0
on