Broken Gear Box on a Freeway.


The most common cause of a failed gear box is the axle blocs. These are the two plastic parts attatched to the frame on either side of the gear box, which the axle runs through. Over time these can wear into an oval shape which allows the axle to travel up and down. These causes the main cog in the gear box to tilt from side to side and wears the teeth unevenly until it fails, usually causing a loud ratcheting noise.


Replace the axle blocs at the same time as the gear box to prevent further problems. You can find them here along with the gear box, which you will need to search for as they are model-specific.  The search box is at the top right of the screen.