Alison Tranny Retarder vs Jake Brake

[Gary & Peggy Stevens]

Thanks guys for the replys. From what I am hearing I believe that my jake braking operation was changed. It works with the cruise on, which I want, and I can feel it work but only a little currently so I will have someone get in and check the set up of this system and evaluate.

To have it serviced at DD or Alison what exactly are they servicing? The DDEC IV computer or something else. In other words is it a computer controlled issue or mechanincal adjustment?

Thanks Again.

Gary S.

[Steve Bennett]

Gary, an Allison dealer can set & verify the transmission parameters via a lap top. You can have the transmission programed to try to down shift to a specific gear when the throttle is released & the Jake is on. Typically, you will see them set to try to get to 4TH gear. There are also solenoids in the valve train of the engine that can fail, or not fully engage. These can be checked by a Detroit shop.

[Ray Davis]

When I was in FL picking up my bus, the technician mentioned that you can have the jake brake setup for "aggressive" mode. I don't know if this is fact or not, but I wouldn't be surprised, since as Steve indicated they are programmable.

My new coach, and as I remember none of my previous coaches automatically downshifted. I have to manually downshift in areas where I want more braking.

Ray