My neighbor just bought a new 2013 Fleetwood Expedition 40X with a 360HP Cummings and Allison transmission on a Freightliner chassis. We were talking about the "Retard" button and he said the owners m...
I think some of the problem here is simply the word "retarder." It can be used as a generic term for different supplementary braking systems. For example, my last coach had a transmission retarder and my present coach has an engine compression brake. Both systems are referred to as retarders.
I hope the OP didn't send this thread to his pal. He'll be like in the Exorcist with his head turning 360 degrees. jor