HT-741 shifting pattern

[77newell]

Hey all (well actually only those that have or had recently enough to remember), I have a question about how your electronically controlled Allison transmission hooked to a 2 stroke Detroit Diesel shifts. My 93 coach upshifts only when the engine has reached maximum governed speed which is 2100rpm and will stay in that gear unless road speed really drops no matter what I do with the throttle. With the 77 old school mechanically controlled Allison if as speed started to drop going up a hill I mashed the throttle the transmission would downshift a gear. The newer coach doesn't do that. How does your coach work?

The newer ATEC (I think that stands for Allison Transmission Electronic Control or something close) have an input for throttle position (TPS - throttle position sensor that feeds both the engine ECU and the ATEC. My 93 coach has that input disconnected. When I asked the Newell factory about that I was told that that was intentional to improve fuel mileage. I can see how avoiding constant downshifting could decrease fuel mileage but it is also distracting to have to manually downshift when going up hills to prevent lugging the engine.

I believe it will be easy to connect the TPS, but I don't know if the ATEC module will then also need reprogramming. I'm trying to find information just in case I decide to at least try it.

Again, how do your coaches work?