It's important to tighten up the wheels properly, otherwise they vibrate loose and falloff.
把车轮拧紧很重要,否则它们会振动而松脱。
《柯林斯英汉双解大词典》
2
To evade Mexican police and immigration authorities, the children jump onto and off of the moving train cars. Sometimes they fall, and the wheels tear them apart.
为了躲避墨西哥警察和移民局官员,孩子们在火车行进时上蹿下跳,有时会摔到车底,被车轮碾得粉身碎骨。
3
Without her the wheels would falloff this fast moving train.