the belt on my tredmill is shifting (sliding)to the left.causing it to shre?

If the two rollers are not perfevtly parallel, the belt will shift.

One of the rollers, probably the back one, should have alignment screws. There is probably some cover hiding them.

Using a screw driver or some keys, adjust the roller so that it's parallel to the other. The belt will stay in position when the roller is properly set.

Electro
July 2013