What Makes a Good Trans Temp Gauge?Fitting a Transmission Temp Gauge can be easy if you have the right information. Knowing where to put the temperature sensor so that it picks up on the hottest temperature point is the most important factor in having reliable feedback.
Most automotive transmissions have two cooler lines that allow the fluid to flow through the oil coolers. One will be a ‘Hot’ line, with the other being the ‘Cold’ line. The ‘Hot’ line has oil flowing from the transmission at its hottest point, and this is what we want. Using the ‘Cold’ line is going to give you false readings, as this is oil that has been cooled already. This is quite frankly pointless as you are getting a delayed temperature...
We have seen the occasional trans temp gauge with the sensor drilled and fitted to the automatic transmission pan. This is quite frankly pointless, as you are getting a delayed temperature due to the cooled oil mixing with previously cooled oil. This can result in a delay of many minutes, which is potentially disastrous for your transmission as you may continue to push the transmission when it has already reached its critical temperature.
All of our Transmission Temperature Gauge Kits come with replacement cooler union fittings for the ‘Hot’ line, with the temperature sensor already fitted. We also use high temperature silicone insulated wire for the sensor connection, as it is quite often run through the engine bay and close to the exhaust system.