Anyone have a duramax/Allison combo?

james40

I'm having trouble remembering how to activate the grade break going downhill. Tow/haul on, set to any gear besides first, then tap the breaks to engage. Does that sound accurate? If I downshift out of drive, should I leave t/h mode on? Thanks.

firetruckguy

My dad has a 08 and his works when you pull the shifter lever down one notch from drive and use the push buttons on the shifter lever.