740 code Archives - Transmission Digest
More Torque-Converter Forensics

Try to imagine the difficult job tech-line technicians have. They are asked to decipher bits and pieces of information that may not be accurate and then come up with the correct answer. The information the technicians collected for the following two scenarios seemed to be as different as night and day. The information even originated in different countries. The amazing thing about these different complaints and symptoms was that they all had the same root cause.

Blame the Torque Converter – Part 1

Society often influences us to try to blame others for our problems. From an early age we try to place blame with friends or siblings. Our training usually continues into our school age, when the guilty person is always “the other guy.” It seems only natural for this mindset to continue into the workplace. This is especially true if your workplace happens to be with the automatic-transmission industry. The mysterious inside of a sealed torque converter is easily substituted for the “big dumb kid” in the back of the classroom. The following are examples of a torque converter being unjustly blamed for a transmission problem.

TCC Apply Piston & Cover Deflection

A 604 transmission with a 740 code led to many different approaches and attempts to troubleshoot the underlying problem. As the possible causes were narrowed down, the focus began to turn toward the converter. Replacing the converter with a factory unit eliminated the 740 code, and since the code would show up on any road test, this seemed like the perfect vehicle to identify the root cause.