A door prop assembly for selectively supporting a rear gate of a tilting vehicle. Said door prop assembly is configured to selectively prop said rear gate in an open configuration and safely release said rear gate to transition to a closed configuration. Said door prop assembly comprises a prop arm assembly, a lock bar assembly, a distal mount assembly, and a rotating lock arm. Said distal mount assembly is attached to a side portion of said rear gate. Said lock bar assembly is attached to a side portion of a tilting body. Said prop arm assembly comprises a substantially straight element being adapted to slide through portions of a lock bar of said lock bar assembly. Said rotating lock arm is configured to rotate freely on a locking hook hinge. A side plates at a distal hinge is configured to rotate freely relative to said distal mount assembly.