When you buy a treadmill the underside of the walking belt is prelubricated, and the belt/deck system has a friction coefficient (FC) that is optimal per the oem. Inevitiblity, as time goes on the FC level increases (from change in material from use, and the amount of silicone between the belt and deck), thus causing more stress on vital treadmill components. The good news is with periodic maintenance you can dramatically slow this natural progression down.
Due to the fact liquid Silicon evaporates (with or without use) it is recommended you apply it every 3-4 months. This is not novel information, but a lot of people take the information and try to hack it by using a spray bottle and squirting little bits of silicon on the edge while it's folded up, or worse unfolded. Unfortunately, the silicon never reaches the center of the belt where your feet are striking the surface thus is ineffectual. Technically, the proper way to apply lubricant is to take tension off the belt at the rear roller, with that newly created slack you can really get to the underside of the belt at the center. The last step is realign and re-tension the belt at the rear roller as before, kind of a pain, no?
There is one tool that serves as a work around, that is the treadlube applicator and sponge. Simply put, it allows you to apply silicon to the sponge end and with its extension get in to the right underside section of the belt, in the center as described above. We sell them through the link below, lowest price you'll see with shipping.
https://www.hydrafitnessexchange.com/part/treadlube-silicone-lubricant-oil-tread-lube-w-applicator/150912
End Note. You may have stumbled on this because you have belt "slippage" or hesitation issues, please make sure you properly adjusted and tightened the treadbelt.
Related Topics:
Treadmill Motor Or Controller Issue, OR... Is it Friction Coefficient?