Ford 2003 Mustang Workshop Manual page 1421

Installation
1. NOTE: The crankshaft pulley must be installed within four minutes after applying the silicone.
Apply silicone gasket and sealant to the Woodruff key slot on the crankshaft pulley.
2. Using the special tool, install the crankshaft pulley.
3. Install the bolt and washer. Tighten the bolt in four stages.
Stage 1: Tighten the bolt to 90 Nm (66 lb-ft).
Stage 2: Loosen the bolt one full turn.
Stage 3: Tighten the bolt to 50 Nm (37 lb-ft).
Stage 4: Tighten the bolt an additional 85 to 95 degrees.