Jeep Cherokee XJ Forum

Good idea. I have been thinking about putting a transmission oil temperature gauge in mine and on a friends XJ too. The AW4 is a good reliable automatic transmission but it is known to make too much heat. Looking online I have found a number of kits for this. Most are expensive because they often are part of an aux cooler system. There even seems to be some debate on where one should monitor the oil temperature. Temp of the oil coming out of the transmission is hottest vs oil temp as it is returned to the transmission after going through the cooler. The latter seems to be a favorite as it tells you more about how hot the entire system is. Most agree that the pan is the least favored place to monitor trans temperature.
It sure seems like any temp gauge that goes up to 300 degrees would work. Problem is most water temp gauges only go up to 260 degrees. Would also need to make a chamber to mount the sender inline on the trans cooler return line. The end of the sender needs to be immersed in the circulating oil to see the temperature. That would take a little fabbing. One could cut the rubber part of the line and insert the sender chamber inline. Barbed fitting and hose clamps would do it. A 1/2" pipe tee with bushings to reduce the ends to 3/8 barbed hose fittings. Assuming a 1/2 pipe sender. Or you could get fancy and buy the quick connect ends at an auto parts store and connect the sender chamber at the quick connector under the radiator. If you don't already have an extra trans oil cooler now would be the time to add one.