change gear set

例句：

1. 1. The mechanicchanged the gear set on my car tomake it run smoother.
   机械师更换了我的汽车的换挡装置，使车子运行得更加顺畅。
2. 2. The engineerhad to change the gearset in the transmission to fixthe problem.
   工程师不得不更换变速箱中的换挡装置来解决问题。
3. 3. The driverhad to change the gearset to go uphill,as the normal gear was too low.
   司机不得不改变换挡装置以爬坡，因为正常的档位太低了。