engine brake and transmission shift points

[JeffN]

I come down a steep hill on my way home and will use the engine brake on my 2020 3500 6.7. Lately I have noticed that down around 30-35mph the truck will downshift and run the RPM up to damn near the top of the range. Does the engine brake alter the shift points in the Aisin? I have experienced this unloaded and with my trailer, which unloaded is about 4,200 lbs.

 

[RedneckHippy]

Yes, you gotta hold higher RPM for an exhaust brake to be effective, since they did away with the manual your computer does it for you. I have the hemi with the 8 speed now and when braking under coasting it automatically downshifts to assist in slowing down... I just wish it was as aggressive as you describe.

 

[Travelin Ram]

Cummins rates the engine for a higher RPM under braking than it does under power.

In my Freightliner the 6.7 is governed at 2500 under power and 3000 when braking.

 

[JeffN]

thanks, very helpful