During our recent install and test of our Heatshield Pipe Armor and Muffler Armor exhaust insulation kits, we noticed something on the Jeep JK Wrangler. The exhaust system Y-pipe that connects the passenger side exhaust manifold to the system passes right underneath the automatic transmission pan. And within close proximity to the bottom of the pan. This means a lot of heat being radiated upward into the pan, adding heat to the pan and the fluid in it. Not a good thing for ATF life and the transmission in general.
With some Heatshield Armor exhaust insulation left over from the previous test, we decided to see what difference it would make to insulate the pipe and keep the transmission pan cooler. Follow along and see what we found out.
ABOVE: On the 2007-2018 Jeep Wrangler, the Y-pipe that connects the passenger side exhaust manifold to the exhaust system passes only 1.5-inches below the transmission pan. This unshielded pipe is radiating heat upwards right into the aluminum transmission pan, which then transfers that heat to the fluid.
ABOVE: Using our contact probe, we wanted to measure how hot the pipe was getting (with the Jeep running) once the engine was up to temperature.
ABOVE: We measured 278.4 degrees F on the exhaust pipe.
ABOVE: There wasn’t quite enough space to get the contact probe in properly for an accurate reading of the pan temperature above the exhaust pipe, so we had to use the laser thermometer to see how hot the pan was getting. The laser measured 186 degrees F.
ABOVE: Nice thing about the modern Jeep Wranglers, the data display gives you lots of useful information, including transmission fluid temperature. As you can see, the ECM was reading 224 degrees F for the fluid temp.
ABOVE: We had a long enough piece of Heatshield Armor exhaust insulation leftover from our previous test blog to use on the pipe running underneath the Wrangler’s transmission pan.
ABOVE: Before installing Heatshield Armor, once you have the correct sized piece for your install cut out, you need to trim back about 1/4-1/2 inch of JUST THE INSULATION then fold the exposed foil backing over onto the edge of the insulation to give the Armor a finished edge.
ABOVE: Using Heatshield Products HP Ties we secured the Heatshield Armor to the pipe, then took the Jeep for a multi-mile drive to get it up to normal operating temperature before pulling back into the driveway, letting it sit idle for the same amount of time as before, then taking our after readings.
ABOVE: As before we used the laser thermometer to see how hot the pan was getting. A reading of 150.5 degrees F showed us a 35 degree drop in pan temperature after installing the Heatshield Armor on the exhaust pipe under the transmission pan.
ABOVE: Back inside the Jeep, the ECM read automatic transmission fluid temperature at 203 degrees F, a drop of 21 degrees in fluid temperature. These are significant drops in temperature that will help improve ATF longevity and improve protection.
