"I enjoyed putting this together and having a background in mechanical design engineering (retired) i have enjoyed the lego technic line. I only had one problem with the set when i loaded and tried to set the controller on my ipad i found the dump control moved forward. I could not get the box to lift or lower. I took the chassie apart and had to reposition the shift cam from what was shown in the assembly manual and now everything works. I am not sure if it shifts from 1 to 2 but that is ok. I am satisfied with the kit and still give it a good rating."