A toy having a pivoting member such as a dump bucket or bed, with an automatic locking system on the pivoting member. An embodiment of the present invention provides toy having a chassis, a pivoting member pivotably and slideably mounted on the chassis, and a latch mechanism. The pivoting member pivots with respect to a pivot axis and slides in a direction radial to the pivot axis from a first position to a second position. The latch mechanism engages the chassis with the pivoting member in the first position and prevents the pivoting member from pivoting, and disengages the chassis from the pivoting member in the second position to allow the pivoting member to pivot.