[RC-Monster Mike]

The hardened pede/rusty idler is the same dimensions as the stock idler and aluminum Traxxas idler. The aluminum idler gets sharp from running against the steel input gear, which leads to stripping the diff gear. The hardened idler will be the strongest tranny component and won't sharpen itself against the input gear, so the stock diff gear will last a lot longer. We also carry a steel/aluminum diff gear for those looking to run high HP through these little trucks. The aluminum tranny case also minimizes flex inside the tranny, which again allows the gear mesh to stay constant and minimizes any potential stripped gears. :)