Gear tooth thickness at the site are unilateral wear, so gear can be rotated 180 degrees to use.
齿轮在齿厚部位都是单侧磨损，所以可将齿轮翻转180度使用。
2
The utility model relates to slipping-back preventing device for automobile. The utility model is characterized in that the wall of the gear box is provided with a unilateral rotating wheel;