Originally Posted by curtsr
Would prefer that the transmission shift from 6 to 5 before 4. As I mentioned the jolt is severe to the point i worry about the drive shaft or u-joints failing.
The engine brake can be programmed to downshift to either 4 or 2 when it engages. I too don't know anything about an "engine brake select" switch.
I have sometimes noticed a hard downshift on mine, thinking it is most likely to occur on a more gentle grade transition, particularly with cruise control involved. I am rarely able to predict it, and it doesn't happen that often on mine.