AX4S Archives - Transmission Digest
A Tale of Two Fords

Our first tale is one of those situations in which you are in the middle of nowhere and all of a sudden a warning lamp comes on. This person, whom we will call Mr. Public, was driving his Ford Taurus equipped with an AX4S on a lonely stretch of road at night when suddenly the transmission-temperature lamp came on. Fortunately, Mr. Public was able to limp the car into the closest town, where he took the car to the local transmission shop the next morning.

A Keen Perception of the Obvious

A no-move 1992 Mazda MPV van was towed into a shop, where it was determined that the planets inside the R4A-EL transmission were toasted. One look at the vehicle and you can see why (see Figure 1). This van recently had been involved in a front-end collision that collapsed the oil-cooler line, causing a lack of cooler flow, and there ya go – wasted planets.

AX4S or AX4N?

Their turbine-speed sensors look similar but won’t interchange.

At first glance you might think the AX4S and AX4N turbine-speed sensors are the same. However, a closer look will show you that the AX4S sensor is a little longer – which means you easily could install the wrong sensor in a unit by mistake.

Fun with Fords

As almost all of us are aware, a technician can easily create a scary nightmare when trying to mix and match parts while making repairs to some of Ford’s automatic transmissions. A classic example of this is interchangeability of the lockup solenoid (LUS) for the 1991 AXOD-E (AX4S) transaxle.

AX4S/AX4N – No Go/No Charge

With their fingers crossed and the cooler-return line still in the bucket, they start the car up. The cooler line makes a little pop, a spit, some foamy fluid then, lo and behold, a nice clean steady stream of fluid comes out of the line. Mission accomplished. The converter has charge. After the cooler line is re-connected, the trans is topped off, road tested and everything works perfectly. End of story you say. Not quite yet. The question that remains is what did we do to correct whatever was wrong with the unit? We did not find anything to point a finger at as to the cause of the problem.