I cannot stress strongly enough: The single MOST IMPORTANT ongoing maintenance routine that you, the treadmill owner must do is to REGULARLY LUBE YOUR TREADBELT AND DECK,
This will prevent premature treadbelt and deck wear as well as prevent the possibility of the motor control board from be damaged and needing to be replaced and the potential of other repair related issues.
For most treadmills 100% silicone oil is used. When a treadbelt is new the underside has an absorbent fabric weave pattern that holds the silicone oil keeps the treadbelt and deck lubricated. This provides two functions. It keeps the belt and deck from wearing out so quickly as well as puts less stress on the motor and motor controller due to less friction.
For regular ongoing maintenance I would recommend that you apply about an ounce of silicone oil directly to the entire deck. If it has not been lubed in a while or if the deck feels completely dry I would recommend applying two ounces.
For heavily used residential treadmills I would recommend that you lube the treadbelt and deck quarterly. For lightly used treadmills, or perhaps treadmills that are only used in the winter months I would recommend lubing the treadbelt and deck annually at a minimum. I can perform this annually when I perform the recommended annual service.
One of the services that I perform on annual service call is an DC Amp Draw Test. This allows me to determine if the treadbelt and or/deck are worn out and need to be replaced to prevent damage to the motor controller and other components.
Once the treadbelt fabric is worn out underneath, it no longer will hold silicone oil. In addition the now smooth surface under the treadbelt acts like a windshield wiper and will wipe any applied silicone oil to the sides under the pressure of foot traffic. Thus the friction and DC Amp Draw will be instantly as though no lubricant was ever applied at all.
Once the fabric has worn off the underside of the treadbelt enough so that the harder pvc part of the belt begins to wear the deck causing wear grooves in the treadmill deck surface.
When this begins to happen you may need to replace the deck as well. You can feel for this by sliding your hand under the treadbelt in the area where you feet land. Typically when the belt is worn out you will begin to feel these grooves on the deck surface.
I think that it is a good idea just to simply replace the treadbelt every three years on treadmills that are well used. For treadmills that are not used as much you may be able to get by with going five years before replacing the treadbelt.
You can find 100% silicone oil often directly from the treadmill manufacturer. You can also find it locally at Dicks Sporting Goods as well as on Amazon. To apply the silicone oil I personally loosen the two rear roller bolts typically found on both sides at the rear of the rear on the treadmill. Exceptions are 40% incline treadmills like the Nordictrack X16 and the X22i. They are on the front the the treadmill.
I loosen both bolts counter-clockwise 8-10 full turns counting precisely as I go. This allows me to put the tension back exactly as it was when I am done by tightening clockwise the same 8-10 full rotations.
Once loose I then lift up the now loose treadbelt from the side and apply the silicone oil right on the deck in. a zigzag pattern going right down the deck. Don’t worry about this too much as as the oil will spread itself while the treadmill is being used. Be sure to clean up and spills or drips as silicone oil is slippy.
Once done make sure the the belt is centered side to side then tighten the bolts back to their original tension. I then start the treadmill on a slow speed to make sure that the treadbelt stays in the center. If you need a slight adjustment you can move the treadbelt to the right by tightening the left bolt ¼ turn at a time in two minute intervals. Or you can move the treadbelt to the left by doing the same thing to the right bolt.
As a rule of thumb you can check for proper tensioning or tightness of the treadbelt two ways. One is to straddle the treadmill with your feet on the floor and slide your hand under the treadbelt palm up at the about the midpoint of the belt. You should be able to lift and deflect the treadbelt about 2″ off the deck. The other way to test for safety’s sake is to run the treadmill at about 2 MPH and see if you can make the belt slip by stomping down on the treadbelt with one foot while the other rests on the side rail. If for belt slips it is too loose.
There are other means of lubing the treadbelt and deck that do not require loosening the treadbelt. One is by using a wand that has a sponge on it that allows you to apply the silicone oil to the sponge. Then you slide the wand under the treadmill and work it across and then up and down the deck. My personal issue with this method is it wastes silicone oil. You can never get all of the oil out of the sponge onto the deck. These are available on Amazon as ‘LUBE-N-WALK’ and also available locally at Dick’s Sporting Goods, perhaps under another name. Another means is to purchase the silicone oil that comes with bottle that has a long tube that can be side under the belt. This can also be found on Amazon as well as locally at Dick’s Sporting Goods.