T270 Exhaust brake Downshifts

Try turning off the engine brake.

 

Yup that's perfectly fine and factory programed. Remember its like the cummins in the dodge pickups and are built for higher RPM's then its bigger brothers. The smaller the engine the faster it can and is designed to turn.

 

I have a different truck that does similar things. I usually only turn it on when needed. The first down shift is fine but the second is a bit alarming. If I slightly depress the accelerator pedal it does much better. If it increased engine braking with heavier brake application that would be fine but it down shifts like it always an emergency stop. Mine down shifts on cruise the same way so I frequently turn it off in rolling hills. To bad it derates the horsepower at the same time. Poor programming!

 

So that truck has auto tranny then right? the trick usually should be to set it to manual and that should lock out auto-downshifting. Then you just manually lock it in gear you want and control the eng brake stages and downshifting as you go. Thats been my experience in freightshakers anyway. Otherwise it over-revs itself. Freightliner told me it can't hurt itself, but then why does truck throw and record a code for over-revving?

Do what Boxcarkidd above does, turn brake off in rolling hills. If grossed out and going down steep hills/mtns, put it in manual and control eng brake yourself.

 

Its going to be an Allison auto and if I remember right they dont have a manual mode( I could be wrong) but he should be able to hit the upshift arrow to get it to drop the rev's but that also reduces its braking ability. That little engine wont over rev tell past 3500rpm.