I am starting to hear a sound similar to gear backlash which appears to be coming from my Levo SL motor. I don't hear the sound when I can maintain constant rotational pressure on the pedals (pedaling on smooth trails) but when riding down hill coasting over bumps, hitting small drops or when I am pedaling over rough terrain, I can hear the sound. Is this the beginning of the end of my motor? Will it run until it ceases? I am the second owner of this bike so I think I am probably out of warranty. Any idea how much a motor costs if that is the problem?