Locate the two rear roller adjustment bolts that are located in the rear endcaps of the belt. Loosen the walking belt using the Allen wrench five to ten turns, until there is just enough room to get your hand underneath the belt.
Loosen the bolts an equal number of turns and mentally record how many turns you use to loosen them. You will need to tighten the bolts back to the same point you began at when you are finished.
Clean the deck with a fresh cloth to remove any debris or dirt.
Begin approximately 18 inches from the motor cover and squeeze out the entire tub of lubricant onto the very middle of the deck surface in a line parallel to the motor cover. Be sure it is applied in an equal distance from both sides of the belt. The line should be 12 inches in length and resemble the width of a blob of toothpaste upon a toothbrush.
Tighten the rear roller bolts back into position the same number of turns you used to loosen them earlier.
Turn the treadmill on at a speed of six mph and let it run, without walking on it. Wait two minutes to ensure the belt remains properly affixed to the middle of the deck. If is sways to one side or the other, follow the directions in your manufacturer's guide to fix it. A copy of the guide for the XT175 and X275 is located in the Resources section of this article.
Continue to run the treadmill at six mph and begin walking on it after the two minutes are up. Walk on the treadmill for an additional five minutes to make sure the lubricant becomes evenly distributed on the belt.