No Reverse
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 Mercury Grand Marquis, 2002 Lincoln Town Car, 2002 Ford Crown Victoria, 2001 Mercury Mountaineer, and 2001 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
Fluid level and condition, shift linkage, low/reverse clutch pressure, low/reverse band pressure, low line pressure, filter (plugged or damaged), valve body (No. 6 shuttle ball, manual valve, main regulator valve), incorrectly tightened valve body bolts, valve body gaskets damaged, 1-2 accumulator seals stuck or damaged, reverse servo seals damaged, reverse servo cover retaining ring damaged, pump assembly or gasket damaged, reverse clutch assembly, low/reverse band or low/reverse band anchor pins damaged.