Chuck (the OP),
Interesting topic and what a coincidence ... as I just spent an hour researching this before reading your post above!!
You might want to continue some research into this OBDII gauge too:
http://www.ultra-gauge.com/ultragauge/It appears that getting at Ford 5R110W transmission temperature in real time - easily and inexpensively through just plugging in a cable and sticking a guage on the dash - may be a bit tricky (we're not into mobile phones). I definitely like the Ultra-Guage price and information/links on their WEB page ... but some time on the phone with them might definitely be in order before ordering one for your 5/6-speed transmission.
I think I've decided, instead, to merely drive our E450 V10 motorhome a LOT MORE - if not permanently - with it's TOW/HAUL mode turned ON. The fluid color in our failed 5R110W transmission was still a nice healthy pink color - indicating that maybe not a lot of over-heating had taken place prior to failure. Our remanufactured 5R110W transmission up-shifts and down-shifts when in TOW/HAUL mode a lot smoother than the original 5R110W transmission did when in TOW/HAUL mode, so it's more responsive and smoother to drive now in this mode at all times. In this mode down-shifted gears when going up grades are held longer, so heating from the torque converter slippage is probably going to be reduced from the regular mode that I used most of the time previously ... just in case heating had anything to do with why my transmission failed prematurely. I also now will go up grades by keeping engine RPM below around 3800 ... no more of the 4500 RPM stuff. Even though the V10 may not care ... the transmission may not like it!
I'll follow this thread to see what others recommend. Automatic transmissions are no longer inexpensive.
NOTE!!!: I just checked under the hood of our 2005 E450 6.8L V10 Class C and it's smog sticker stated it was OBDI compliant .... no mention of OBDII. This might be very important when shopping for a guage to capture 5R110W transmission temperature.
