I know 200+ operating temperatures are supposed to be normal on the
6R140 transmission but I've never felt comfortable with it running that high. On a couple of instances it reached the 230° range pulling long steep grades in Colorado.
After much research I decided to install a Mishimoto transmission cooler and it has dramatically lowered my temperatures. The before and after pictures are both with outside temperatures in the high 90's to low 100's on relatively flat ground. On a recent climb to Big Bear, CA via CA 38 the highest I saw was 172°.
Install was pretty straightforward.
Linear Mode
