I think it would be easier to animate the maps (tex, bump and trans or whatever combination) if your model is build in a fashion that would allow it. Go to the material room. Click the tiny little key next to U_Offset and/or V_Offset and click on "Animate" from the drop down that pops up. Then go to the appropriate frames and start keyframing by changing the U and/or V Offset for the maps for the treads as needed.