One problem related to transmission slip out of gear has been reported for the 2002 Ford Windstar. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Ford Windstar based on all problems reported for the 2002 Windstar.
Overdrive light begins flashing and overdrive shifts out ogf gear. This problem has happened on two consecutive Ford Windstars I've owned. A 1999 and 2002. Both problems occurred at the 120,000 mile mark. In both cases the transmission was diagnose as needing replacement. In both cases the flashing o/d light came on again after the transmissions were replaced at great expense. This time I replaced the trans in the 2002 with a trans out of a 2005 with 52,000 miles on it. Now 2 months later the light is flashing again but the overdrive seems to be functioning properly. In the case of the 1999 I had to replace the abs control module after replacing the trans which I believed might have fixed the problem, but I don't know for sure because I dumped the vehicle quickly afterward. In this case I'm going to trade in the 2002 on a Chrysler pacifica.