I'm installing a new timing belt on my son's MP5. Once the valve cover was removed, we found that the belt was stripped of most of it's rubber cogs and was off the rear camshaft pulley. With the motor at TDC, I can't seem to rotate the rear cam shaft pulley to align the I and E marks. Is there a certain way to do this or am I looking at another problem?? any info would be great!! Thank you