A windshield wiper arm assembly that is adapted to support a wiper blade as it moves across a surface to be wiped. The windshield wiper arm assembly includes a body and a head supported by the body and adapted to be mounted to a pivot shaft that defines a pivot axis P and drives the wiper blade in an oscillating manner across the surface to be wiped. The body also includes an opening providing access to the head mounted to the pivot shaft. A cover is mounted to the body at the opening and is movable about an axis A substantially parallel to the pivot axis P from a first position closing the opening to a second position allowing access to the head.