Why Does my Garage Door Opener Travel Less than 6 to 8 Inches After Replacing Internal Parts?

This article will walk you through how to resolve an issue where your Garage Door Opener is traveling LESS than 6 to 8 inches after replacing internal parts such as the Motor or the Gear and Sprocket Assembly.

If after replacing the Motor or the Gear and Sprocket Assembly, the Garage Door Opener travels less than 6 to 8 inches, check the motor shaft for movement, otherwise known as "End Play" in the motor shaft.
 

Check the Interrupter Cup and RPM Sensor

1. Unplug the Garage Door Opener from AC power.

2. Remove the metal cover.

3. Verify both the Interrupter Cup and RPM sensor are installed correctly. 
   
     

4. Verify the wire harness is connected properly both at the RPM sensor and at the Logic Board connection points. Check to make sure that all metal prongs from the the RPM's chip are plugged into the wire harness. The same goes for the logic board end of this wire harness. Both are items that are located towards the end of the motor shaft.

• If they were not installed, correct and try to cycle the opener before proceeding.
• If you try this and it does not work, make sure to remove the plug from AC power before proceeding.
• If they were installed properly, proceed with the next steps.

Check for End Play

Be sure to refer to the instruction sheet which came with the motor or gear and sprocket assembly for visual steps on how to correctly install the shaft bearing kit.

1. Loosen the set screws on the shaft bearing.

2. Press firmly on the motor shaft then press the shaft bearing into place.

3. While holding all together, tighten the set screws.

4. Test shaft for movement. Place 2 fingers on the motor shaft to verify the shaft is not moving more than 1/16 of an inch.

• If it does, repeat until the shaft does not move more than 1/16 of an inch.
• If it does not, proceed to the next step.

5. With the cover off, plug the unit into AC power.
6. Reset your travel and force adjustments. See: Overview article: How to find the right article to adjust the travel and force limit.
7. Cycle the opener from the wall control.

• If the unit travels more than 6 to 8 inches, the motor shaft is set properly.

• If it does not travel more than 6 to 8 inches and the shaft does not move more than 1/16 of an inch, see additional items to check

Additional Items to Check

1. Verify the interrupter cup is fastened all the way on the motor shaft.

2. Verify the RPM sensor is installed correctly

• Unplug the RPM sensor.
• Take the sensor out of the bracket.
• Clean the sensor with a Q-tip dipped with rubbing alcohol (ethyl alcohol or isopropanol).
• When the alcohol evaporates reinstall the RPM sensor into the bracket.
• Plug the wire harness back in.
• Test the Garage Door Opener from the wall control.

  • If cleaning the RPM sensor results in travel of 6-8 inches or less, replace the RPM sensor. See your products owner's manual for the correct item number.
     

Additional support articles you may find useful:

• How To Adjust The Limit Or Travel On A Garage Door Opener With Manual Adjustment Screws

• How To Adjust The Force On A Garage Door Opener With Manual Adjustment Screws

• How to resolve issues with an out of phase chain/belt drive opener