AX4S/N Archives - Transmission Digest
Fluid Change Can Cost Big Change ($)

Some of us may remember how in the days of old a C-6 transmission would leave a beautiful filter footprint in the bottom pan. This resulted from the filter opening being too close to the pan. When the pump started sucking, it would pull the pan right up to the filter, and as it vibrated away the filter etched itself into the pan. Of course, that starved the pump and caused premature failure of the transmission.

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.

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.