Abstract: A system and method for moving and aligning tandem axle lock pins on a semi-trailer, having a viewer and a remote receiver that are placeable in communication with each other. The viewer is attachable to a trailer so that a camera on the viewer can be positioned such that the trailer slide rail and tandem axle slider frame of a trailer are within the field of vision. The remote receiver may be a smartphone which can access data from the camera so that the user can from a remote location, such as a cab of a tractor, determine the alignment and orientation of the trailer slide rail and the tandem axle slider frame.