[77newell]

Interestingly, despite having the electronic version of the transmission, I too, have to manually downshift or the RPMs drop too low before the shift. The reason in my case is that Newell did not install the link from the TPS (throttle position sensor) to the transmission ECU so that the ECU would know what the throttle input is. I'm told they did this to improve fuel mileage. This has created a bit of an issue for me since I installed Transynd. Sometimes on the 2-3 shift or the 3-4 shift the clutch on the new gear slips until I back off the throttle and the clutch can fully grab. There is valving in the transmission that pushes higher oil pressure to the clutches 3 and 4 whenever the TPS is greater than 60%. The intention of the design is that you get softer shifts with lower throttle and harder shifts with higher throttle. I plan to talk with an Allison dealer to find what solutions are available.

If you have a mechanical transmission there should be an air signal from the air throttle going into the tranny to accomplish this same purpose. It worked on the 77 coach with the HT740.