How do I change the springs in a large PlexiDor dog door?

Door SeriesThe large PlexiDor dog door has a spring on each side that closes the saloon-style panels once the pet has gone through. It’s easy to change the springs, and the spring replacement kit contains these step-by-step instructions.

Besides the spring kit, you will need:

  • 3/8 inch nut driver
  • 5/16 nut driver
  • Vise grip/locking pliers
  • Phillips head screwdriver
  • Flathead screwdriver

The springs aren’t accessible when the door is mounted, so the first step is removing the interior frame from the house door or wall where it has been installed. Just unscrew the four retaining screws in the inner frame and slide it out of the hole.

Remove the spring hoods by unscrewing the hex-head screws and lifting the hood over the rivet head.

Spring hoods on a PlexiDor dog door

If your door is manufactured before 2008, the new springs may be too tall to fit under the spring hood. If your springs end up touching the top of the spring hood or won’t fit, just leave the spring hoods off. If you have any questions, give us a call at 800-749-9609 option 3.

One the spring hoods are off, it’s time to remove the pivot screw that holds the bent arm in position. Use a 5/16 nut driver and remove the old bent arm and spring.

PlexiDor large springThis is a good time to clean the frame. You can use warm water with Dawn to wipe it down. Cleaning it will make it easier to install the new springs, and it will ensure you don’t get dirt and grime in the new spring assembly.

Once all the parts of the old spring have been removed:

  • Push the new pivot pin into the frame with the notched end on top.
  • Put the gray nylon shoulder washer over the pivot pin, with the wide part on top.
  • Put the nylon tube spacer over the pivot pin.
  • Put the spring on the top of the nylon tube

One side of the spring has a tail that points up slightly, and this part should be on the bottom. Using a pair of small wire gripping pliers, grab the top spring tail, wind it around, and hook it over the vertical plate. (As you face the door, the slightly bent spring tail will be in front of the vertical plate on the left spring side. On the right side, the slightly bent spring tail will be behind the vertical plate.)

  • Snap the bent arm onto the pivot pin
  • Place the internal tooth washer on top of the bent arm and slide screw down into the pivot pin
  • Hold the pet door panel in the center of the frame and tighten the pivot pin screw. It should be snug, but not overtigthened.

Repeat for the other side.

You may need to trim the spring tail ends so they extend about 1/16″ beyond the vertical plate. Check that the spring tails don’t touch anything and hinder the door’s operation when the panels are fully opened.

The parts come together in this order:

PlexiDor large spring assembly

When you have made sure the springs are installed right and don’t touch anything when the door panels are fully opened, apply a high quality grease to the spring. We use marine grease for longevity.

Do not use WD40 as grease – it’s a cleaner and not the same thing as grease.

Replace the spring hood – don’t over-tighten the hood mount screws – and slide the pet door back into its mounting hole.

The following video shows the procedure step-by-step.