4F50N Archives - Transmission Digest
Harsh 1-2 Shift

I received a call from one of our wholesale customers, a shop that does general-repair and transmission work on occasion. He was looking for help on a 2004 Ford Freestar that he could not get to leave his shop. In fact, the vehicle had been to several other shops. He told me that another shop had worked on the transmission recently and that it was now back in his shop.

Listen to the Customer

The customer brought his 2005 Ford Taurus to our shop with a complaint of an intermittent jerk at highway speeds. The customer had gone through the trouble of documenting the times that this jerk appeared, the temperature at which it occurred and under what driving conditions he was feeling the intermittent condition. He also told me that another shop had recently rebuilt the transmission. I took the time to listen to him and to ask several follow-up questions that would help me correctly identify the problem. It occurred only once every couple of days.

Point de Non-Retour (Point of No Return)

2004 and later AX4N/4F50N units have a new design for the gasket between the case and case cover. Changes in the area of the neutral/reverse accumulator (Figure 1) required a small change in the opening for the accumulator. The 1.490-inch-diameter opening used on 2000-2003 units was increased to 1.810 inches in 2004.