mine makes a toc.. toc.. toc noise when i back up and turn. or round a corner with the throttle off on pavement. i guess that's normal. sure launches the truck up hills though. i can see why once you put one in the rear diff, you want another one up front. i had a lot of fun trying to get stuck in 2wd.
![Burn Out! :burnout:](https://board.marlincrawler.com/Smileys/marlin/burnout.gif)