Ford 2003 Mustang Workshop Manual page 2836

36. Install the synchronizer springs and inserts.
37. Install the sliding sleeve on the synchronizer hub.
Align the pockets in the blocking ring with the struts in the synchronizer.
The sliding sleeve is not reversible. Install the sleeve with the bevel edge away from the
gear.
38. Install fifth gear blocking ring.
39. Install the fifth gear synchronizer cone.