2005 Nissan Pathfinder SE 4WD 4dr SUV (4.0L 6cyl 5A)
I recently bought a 2005 Pathfinder at a mileage of 110k. After reading scary stories about radiator coolant mixing with trans oil, I decided to take a preemptive measure as suggested, i.e. disconnect coolant line from the radiator and add an external transmission cooler.
I took my vehicle to Volksdoctor. David, the owner, is very nice man.
When he was trying to find a spot for external cooler installation, he found there is a small cooler in the front of the radiator. Then he checked VIN online and found this vehicle has a separate trans cooler. I was so happy about it.
Thus, check your vehicle before you add one, you might have it separated already.