Ford 2003 Mustang Workshop Manual page 1725

Automatic transmission vehicles
1. Remove the flexplate. For additional information, refer to
Manual transmission vehicles
2. Remove the flywheel. For additional information, refer to
All vehicles
3. Using the special tools, remove the crankshaft oil slinger.
4. Using the special tools, remove the crankshaft rear oil seal.
Installation
All vehicles
1. Using the special tools, install the crankshaft rear oil seal.
Lubricate the oil seal using clean engine oil.
Flexplate in this section.
Flywheel in this section.