Replacing a Pedal Arm Return Spring on the Stairmaster 4000PT Stepper
How To Replace a Spring on Stairmaster 4000PT
Remove bottom cover.
Unhook the pedal arm return spring from the spring hanger.
Detach the spring from the step chain by removing the master link. The spring-chain connector is in good condition if it has an hour glass shape. Replace a worn spring-chain connector.
Check to ensure that the spring pulley turns freely and is not worn excessively. Refer to the "Spring Pulley" section if you have to replace the pulley.
To reinstall th spring, connect it to the end of the step chain using the master link.
Route the spring under the spring pulley.
Hook the end of the pedal arm return spring onto the spring hanger. WARNING: Do not twist the spring during installation. It will wear excessively and reduce the life of the spring.
How to Replace Pedal Arm Return Spring on Stairmaster 4000PT
Why does one pedal drop on my Stairmaster Stepper but the other pedal operates correctly?
Stairmaster Steppers, How to Troubleshoot when one Pedal Drops (Loses Resistance) while the Other Pedal Operates Correctly
If one pedal drops while the other operates correctly on your Stairmaster stepper, this problem commonly occurs when the drive sprocket on one side or the other becomes defective
Usually, when one drive sprocket fails, the other isn't too far behind
The best approach to resolve this problem is to install a new hub assembly