Ford 2003 Mustang Workshop Manual page 2559

19. Install the overdrive servo spring.
1. Install the overdrive servo piston return spring.
2. Install the overdrive servo piston.
20. Verify the tip of the piston assembly engages the pocket of the overdrive band.
21. Using the special tool, compress the overdrive servo assembly and install the overdrive servo
retaining ring.
22. Install the intermediate clutch pressure plate.