Will the broken motor bolt cause the drive belt to slip. There are 2 bolts and one is broken off. I guess these are not made very strong.
It's hard to say but, lets assume that with one bold doing the work, it does put this last bolt under strain and will, given time, snap as well and then the whole belt with be damaged or will stop operating. Looks like these 2 bolts are there to hold or tension the belt. You didn't say which bolt is broken, the top one or bottom one, the left or right. You know. A lot of people buy treadmills and use them often but, for the bolt to break, it must be because the belt is running really dry. Do you lubricate the base of the bed (the large plate where the belt slides on and you walk or run on it)? I bet you haven't since you bought it. But let me tell you this, the treadmills are great to practice or do strenuous training, however they're delicate when it comes to running on them without lubrication. Most of the moving components are self lubricated, like the motor, the gearbox and the belt rollers, etc. - they have bearings or lifelong lubricated bronze bushing; whatever they use, it requires little or no lubrication for the life or the treadmill, but the belt that you run on, often gets dry from dust, becomes warm and increase drag, thus overworking the motor until it either cooks out (fuses out) or some things like the bolts snap right off. To make sure that it works lightly and without drag you should spray a quality silicone spray on the bed base. As silicone comes in spray form, this is effective if you have Lino floors but if you have carpet, the spray stains the carpet over time. It's best if you use a lint free cloth, go outside, spray on the cloth and then return inside to the treadmill, lift the belt with your fingers and soak or smear the bed evenly once every months if used sparingly or twice per month is used a lot. You only need to smear the smooth base of the bed, you do not need to apply too much. Just feel with your hand (fingers), if it feels moist or slippery, it's enough. Run the belt slowly a minute before beginning your exercises. Hope it helps.