Desert Captain wrote:
"So....I put the trans in Tow-Haul mode right away, every dang time I remember."
Ron, I occasionally forget to engage TH but my Scan Gauge quickly reminds me as the trans fluid temps begin to rise significantly on even slight grades, :S oops forgot again, a push of the button and with TH engaged they quickly fall back to the proper/normal levels.
You do have a Scan Gauge, yes?
As noted above TH especially on an E-450 should be engaged virtually all of the time due to the weight and aerodynamics {or lack thereof}. What the OP described does not sound right and the suggestion to have the dealer reflash the ECM sounds like the way to go.
I have spoken with a couple of dozen folks renting C's and not one was ever given a syllable of instruction on using TH. This tells me two things, one; most of the folks renting them are blissfully ignorant of this function and two, most rental RV are slowly but surely cooking their transmissions, caveat emptor. :E
Do you have the 6 speed or the 5 speed?
I’m wondering if TH is pretty much recommended full-time even with the newer transmission.