WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Removing/Installing Plug And Center Screw At Variable Valve Timing Unit
Courtesy of VOLVO CARS OF NORTH AMERICA.
Install the timing gear pulley using the center screw on the camshaft.
Ensure that the markings on the timing gear pulleys/upper timing cover correspond. Do not
tighten.