One problem related to transmission shudder has been reported for the 1998 Ford Windstar. The most recently reported issues are listed below.
After backing out of a driveway,from a complete stop transmission made a grinding sound when shifting to drive. Transmission experienced a complete failure after driving 1/2 mile down the road. Ford mechanic informed me that an aluminum part was used in this model year,then Ford changed it back to steel on rebuilt and subsequent year models. Ford never issued a recall on this problem. Dealer said they would replace the transmission for $500 plus deductable for an extended service plan.