Precor EFX Ellipticals, Replacing a Crank Arm

This article covers replacing a crank arm on a Precor EFX elliptical. The crank arm connects the stairarm to the drive assembly in the back of the machine.

The crank arm on a Precor EFX can be replaced one side at a time. The steps to replace one side are the same on the opposite side.

The following are the basic steps for replacing the crank arm on the Precor EFXs.

Tools Required:

  • Pittman Arm Puller or 4" - 6" Gear Puller
  • Screwdriver Set
  • US and metric socket wrench set
  • US and metric end wrench set
  • Allen Wrench set

Steps to Replacing a Crank Arm on a Precor EFX Elliptical:

  Caution

Disconnect power before performing any service operations. Disconnect the power cord (if equipped) from the wall outlet. Disconnect the positive (red) lead from the battery. Movement of the machine parts can cause potentially hazardous voltage, even if the battery is disconnected. Removing the machine's covers exposes you to potentially hazardous voltage and dangerous machinery. Exercise caution when performing repairs. Be aware of moving parts, pinch points, electrical components, and heat with voltage exposure.

 

Removing a Crank Arm

  1. Remove the rear side cover for the crank arm that needs to be replaced. If both crank arms are being replaced, remove both of the rear covers, left and right.
    Do this by removing the 2 screws at the rear of the rear covers. If removing the left side, grab and rotate it clockwise to remove it. Grab and rotate counterclockwise, the right side cover to remove it. You will do the reverse to install the left and right side rear covers.
  2. Remove the stairarm assembly. Click here to read about replacing the stairarm.
    Notice the position of the two crank arms before disassembly. The crank arms must be set 180 degrees opposite of each other.
  3. Remove the bolt connecting the crank arm to the input pulley shaft. If your crank arm is a pinch bolt design, also remove the pinch bolt.
  4. Use a Pitman arm puller or a 4" to 6" gear puller to remove the crank arm. Do not bang on the crank arm. Do not use a hammer or mallet to remove the crank arm. Damage to other parts can occur.
    Note: When replacing the crank arm on the right side, as if on the machine, remove the magnet (when equipped) from the backside of the crank arm shaft. Install the magnet onto the replacement crank arm. The magnet sits in a recess. Use a flathead screwdriver or another piece of steel to remove the magnet. The magnet is found on EFXs that do not have a generator.
  5. Repeat the steps taken for the opposite side if replacing both crank arms.

Installing a Crank Arm

  1. Clean the threads of the crank arm bolt and the threads in the shaft where the crank arm mounts with an alcohol swab.
  2. Allow these to dry and apply blue Loctite to the threads on the crank arm bolt.
  3. Position the crankarm on the input pulley shaft. Thread and hand-tighten the axle bolt into the input pulley shaft. Note: The crank arms must be set 180 degrees opposite of each other.
    For Units with a pinch bolt design crank arm, torque the axle bolt to 200 in/lbs.
    For Units without a pinch bolt design crank arm, torque the axle bolt to 300 in/lbs.
  4. Replace the pinch bolt and locknut, and torque the pinch bolt to 400 in/lbs.
  5. If replacing the crank arm on the left side, as if on the machine, skip to step 6.
    For Units without a generator: If replacing the crank arm on the right side, as if on the machine, install the magnet taken from the old crank arm into the recess on the backside of the shaft of the replacement crank arm.
    Note: Failure to install the magnet will result in no speed reading. Installing the magnet with the wrong polarity can also result in no speed reading. Only machines without a generator have this magnet on the crank arm.
  6. Repeat steps 1 to 4 of installing the crank arm for the opposite side if replacing both.
  7. Replace the stairarm assembly. Click here to read about how to replace the stairarm.
  8. Check unit for operation.
    If the crank arm you replaced had a magnet, you need to check for stride rate. Reconnect the power and turn the machine on. Get on the machine and begin to exercise. Note if the stride rate is displayed. The stride rate should not be 0 while the machine is in motion. If the rate is 0, the magnet is backward. Reverse the magnet position in the crank arm. Flip the magnet over. Once the stride rate displays correctly, set the unit to the highest resistance. Use the motion to put it in motion for 3 minutes. For half of this time, use the machine in the forward direction. For the other half of the time, use the machine in a backward direction. Then re-torque both of the axle bolts of the crank arms to 300 in/lbs.
  9. Reinstall the left and right rear covers. Press and turn the rear right side cover clockwise into place. Press and turn the rear left side cover counterclockwise into place. Reinstall the 2 screws at the rear of the covers.
  10. Be sure to do a final performance check for machine operation.

This completes the replacement of a crank arm on a Precor EFX elliptical.

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