Originally Posted By: AP9
Reading temp on Scangauge II. I believe the OBD-II TFT sensor is in the pan. I'm getting these temperatures both in city driving and highway driving, not towing. It does seem like the trans fluid temp wants to "stabilize" to about water temperature (195F) once it's warm. I don't know if that's coincidence or because of the radiator design.
Yes, most Ford products have a sensor in the valve body (if they have one, not all do). I researched this a learned th reading is somewhat a composite reading of TC temp and pan temp. Some higher than the pan but lots cooler that TC temp. I have a 4R75W in my F150 and can read the OBDII temp as well as pan and cooler line temp. I generally always read OBD and pan temp and they are often pretty close as long as the converter is locked up. In town, OBDII generally reads a lot higher because the converter is locking and unlocking.
My truck has a 9 row factory cooler (it's the 8200 GVW F150) and it has a Mag-Heytec deep finned pan. On a 90 degree day, OBD temp is usually around 160-170.
If your Explorer only has the radiator cooler, your temps make sense. I will say again that the temps you mention would not indicate to me that you have a problem and I wouldn't invest the money in a cooler. Especially a big one. You can go too far the other way as well but it's mostly just a case of diminished financial returns. Going from a normal 200 down to 150-160F will not offer any reasonable payback for the money spent. The caveat is whether you ever do any towing or hauling and see higher sustained temps in that venue. If it stays below short term spikes below 250F and sustained up to 230F and you don't do it often, it will somewhat shorten the life of the oil but the trans will handle it fine.
If you are bound and determined to get a cooler, get a moderately sized stacked unit like the type B&M offers.
The filtration option is definitely worth pursuing. Read this:
Trans Filtration