RE: Redcat vehicle repair/tune FAQ
On the other side of the larger gear, toward the fuel tank, theres a 14mm nut. Holding the small aluminium gear you need to tighten that nut down tight against the spring. This is the slipper clutch. The spring tension pushes the larger plastic gear agianst the smaller gear and theres a gasket-like washer that slips to prevent too much stress on the drivetrain. They can loosen up.