How to check and adjust treadmill walking belt tension and alignment.

   Own a home treadmill and not doing such a good job of keeping up with routine service and maintenance? Don’t feel bad. Many home treadmill owners find themselves in this situation.  For some reason, many people do not realize that the home treadmill is a machine that does need routine service, cleaning, and maintenance from time to time.
   One of the most important things to do for the long life of your home treadmill is to keep the walking belt properly tensioned and aligned – that is tight enough to not slip around the front roller and running mostly right down the center of the deck without rubbing the siderails.  Treadmill walking belts do not need frequent tension adjustment of alignment. Once it is set, the tension and alignment should not change under normal wear and use. If it does change, that means something in the system changed and it needs attention.
  For a brand new home treadmill, the installers or home owner, should check the belt tension and alignment, before placing it in regular use.  How do we do this? 
  For a brand new treadmill, in most cases, the walking belt is tensioned and aligned before the unit is packaged for sale and shipment.  That means when you buy it and take it out of the box, the walking belt should be aligned and tensioned properly and need no adjustment.  However, it must be checked.
  How to check the walking belt tension and alignment on your brand new home treadmill:
  First, assemble the treadmill. Make sure to follow the instructions for assembly  in the owner’s manual precisely.  Follow the steps in order and use good tools. Make sure the walking belt and deck are lubricated with a lubricant that is approved by the manufacturer.  For most home treadmills, this will be a liquid silicone oil.  See the article here on when and how to lubricate!
  Then, when ready, plug the machine in to wall power and turn it on. Give it time to start up and for the console to say “ready”.  When the treadmill is ready to go, we are ready to test the walking belt tension and alignment.
  Before pressing “start”, be sure to read and follow all the safety warnings and precautions in the owner’s manual. 
  Step up on to the walking belt. Stand with the right foot on the right siderail and the left foot on the left siderail, so that you are not standing on the walking belt in any way.  Hold on to the handrails on both left and right sides. Press the “quick start” button to start the treadmill.  In a few seconds, the treadmill walking belt should start to move at a very slow speed of 0.5 to 1.0 miles per hour.  When the belt starts to move, watch it for a few minutes. 
  The walking belt should move smoothly and evenly down the belt.  It should stay mostly down the center of the deck with equal spacing between the edge of the walking belt and the siderails on both left and right sides.
  Note.  You may hear a low, “thunking” type of noise in a regular rhythm as the new home treadmill starts to move.   This is normal. What happens is the belt is tensioned around the front and rear roller in the factory.  Then it is boxed up, shipped somewhere, and sits in storage until it is purchased. During that waiting time, the walking belt conforms in some degree to the curve of the front and rear rollers. When the walking belt is placed in service and starts moving for the first time, the belt is slightly deformed.  As it starts to run, it is normal for it to make a light thunking type noise. 
  Also, the treadmill walking belt has a thick seem where the belt is joined together.  This seem is usually at an angle, so that it runs diagonally across the belt, not straight across.  When this thick seem hits goes around the rollers, it is also normal for it to make a light “thunking” type noise. The noise is similar to the sound your finger makes when you drum it on the table.
  You should not hear any dragging, scraping, or rubbing sounds.  If you do hear those kinds of sounds, stop the treadmill and inspect the walking belt to see where it is rubbing.
   Now that the walking belt is moving and you have observed it running straight down the middle. Observe it running for 4-5 minutes. It should  continue running straight down the middle and not be moving, even slightly to the left or right.
  If the belt is running straight, then it is time to see if the walking belt is tight enough.  When it is tight enough, it will feel solid under foot and not “slippery” at all. To test this, carefully transition to walking on the walking belt. Walk on it at 2 mph and then increase that speed to a fast walk for you.  This may be 3 mph or 4.  As you walk, pay attention to your foot plant and step off. The belt should feel solid underfoot.
   If the belt feels solid, then slowly increase the speed until you are running at an easy, jogging speed for you, somewhere between 5 and 6 mph.  Pay attention to your foot striking the walking belt.  It should feel solid with no slipping feeling.
  If the belt does feel solid, then press the stop button. Your treadmill walking belt is properly tightened.  If it is running straight down the middle and not moving to one side, then it is properly aligned.   The walking belt tension and alignment do not need to be adjusted unless the belt gets loose or starts to move to one side. If that happens, then the tensions and alignment need to be adjusted.
If you have an treadmill that has been used for any period of time over two weeks or 12 hours of use and the belt is loose or feels “slippery” under foot, or if the walking belt is moving to the left or the right, then the tension and alignment need to be checked and adjusted.   Step up on to the walking belt. Stand with the right foot on the right siderail and the left foot on the left siderail, so that you are not standing on the walking belt in any way.  Hold on to the handrails on both left and right sides. Press the “quick start” button to start the treadmill.  In a few seconds, the treadmill walking belt should start to move at a very slow speed of 0.5 to 1.0 miles per hour.  When the belt starts to move, watch it for a few minutes. 
Observe the walking belt in motion.  Does the belt move to the left or to the right?
  For this explanation, lets assume the belt is moving to the right.  Press the stop button and get tools needed to turn the treadmill walking belt adjustment bolts found on the rear of the treadmill deck.  You will most likely need a set of allen wrenches, metric or standard, depending on the manufacturer. You will also need a #2 phillips screwdriver.
    Remove the end caps that cover the belt tension adjustment bolts. There are usually 2 or 3 phillips screws. Pay attention to which screws came out of which holes. They will need to go back in to the same holes when you are done.
   Remove the left and right endcaps. This will expose the left and right ends of the rear roller and the belt tension adjustment bolts.
   Find the correct wrench to turn the belt tension adjustment bolts.
   Start the treadmill again and increase the speed to 3 mph. In this situation, the belt is moving to the right.  This means that we need to increase tension on the right side.  Using the correct tool, turn the right side belt tension adjustment bolt ¼ turn to the right, clockwise.  Let the treadmill belt run and observe.  If the belt continues to move to the right, then add another ¼ turn to the right, clockwise, on the right belt tension adjustment bolt. Repeat this process until the belt just stops moving to the right.  Then add an 1/8 turn to the right, clockwise, on the right belt tension adjustment bolt.
  Your walking belt is properly tensioned. Good job.
   If the belt is moving to the left, then follow these same steps, but on the left side with the left belt tension adjustment bolt.
   If the belt is not centered and is closer to the side rails on either the left side or the right side, then use this simple method to get it in to the middle. 
   Stand on the floor beside the running treadmill.  If the belt is closer to the right side, then stand on the right side of the treadmill.  If it is closer to the left side, then stand on the left side of the treadmill.  Get the treadmill started and increase speed to 3 mph.  Hold on to the handrail on the treadmill. Use your foot to gently kick the moving treadmill walking belt towards the center of the deck. 
  What you are doing is pushing the walking belt sideways with your foot.  Use quick, short kicks.  Avoid kicking forward against the motion of the belt. 
   Kick the belt over until it is about in the center. Observe.  It will re-align itself slightly as it runs and then even out.  It should not be moving to the right or left. If it is moving, then adjust the belt tension.  See the instructions above.