Ford 2003 Mustang Workshop Manual page 1192

1. CAUTION: The timing chain procedures must be followed exactly or damage to the
valve and pistons will result.
Compress the tensioner plunger, using an edge of a vise.
2. While holding the ratchet mechanism, push the ratchet arm back into the tensioner housing.
3. Install a paper clip into the hole in the tensioner housing to hold the ratchet assembly and
plunger in during installation.
4. If the copper links are not visible, mark one link on one end and one link on the other end, and
use as timing marks.