I've looked in the expected places - fluid lines to cooler and the sump. No sign of a temp sensor. The only one I can find is what is labeled (on schematics) as "retarder temperature". I asked Mark and he believed that the 2003 used whatever sensor Allison had, i.e., FT did not add their own sensor as they had done in years past.
So, if anyone KNOWS the actual location of the transmission temperature sensor on a 2003 U320, I would appreciate a hint.
Thanks
Am told it is the sump, do not exceed 250F, this from FOT and Allison Fluid Engineer, Others will always have different opinions certainly
Dave M
Allison provides two temperature outputs, one in the sump, the other in the retarder section. Foretravel uses the sump sender, perhaps because the temperature swings are much faster and higher, and could cause unnecessary alarm and/or concern.
At about 300 degrees in the retarder, the software starts "load shedding", and at about 330 degrees, the "shedding" is close to 100%, meaning the retarder has shut down "retarding".
The Senior Allison Rep advised that 250 degrees in the sump is equivalent to 300 degrees in the retarder section.
Allison Retarder Temperature (http://www.beamalarm.com/Documents/allison_retarder_temperature.html)