Allison gear selection question

[NoMo]

Scenario:
Driving through a parking lot at 10mph and slowing for speed bumps, the tranny downshifts to 1st gear. This requires me to apply throttle to maintain speed. Manually selecting "2" or "3" does not force the tranny to up-shift.

Shouldn't it- or does the Allison not work that way?

[VA_Dmax]

It is my understanding that by putting the trans into 2 or 3 with the automatic only limits its upshift to that gear, and would still allow it to use the 1st gear.

[NoMo]

Too bad. Being able to start off in 2nd gear is a great asset in low traction situations.

[Bobcat698]

What automatics DO allow you to start in 2nd gear?

I can't think of any...

[DmaxMaverick]

Bobcat698

4L80E, 4L60E, E40D, C-6, etc. (I think, but not sure about Torqueflight). Not all applications allowed it, but many did/do. The Allison, being fully electronically controlled, would allow it with appropriate programming.

[NoMo]

DmaxMaverick got it...

All of Ford's truck transmissions (not sure about the new 5-speed) will allow operation in a single gear. Very nice feature when you have a high-torque engine in a low traction situation. Also nice in that when you are driving at a speed that is "in between" gears you can control the shifts.

[Husker Fan]

Agreed,

My old '77 Ford with the 460 and the 3 Speed C-6 transmission would lock into second gear if that is what you selected on the gear shift. I don't think it is that big of deal with the Duramax/Allison, simply because the electronic controls of the Duramax allow you to really