Exhaust Brake 'Mode" in the "Cruise Control Perimeters"

Covers engines and transmissions
05wingrider
Posts: 104
Joined: Sun Oct 27, 2019 7:26 pm
Location: Spokane, Washington

Re: Exhaust Brake 'Mode" in the "Cruise Control Perimeters"

Post by 05wingrider »

Brett,
You state that you have yours set to 5th and are able to use the up/down arrows to change your gear as necessary - is that something that is available to any of the Allison transmissions? Mine is set to 2, but I noticed that there doesn't seem to be any changes allowed (I tried using the arrows last time going down a hill with no change). I think at this point that I'd rather have mine set to 5th for long grades since I'm in the PNW and have hills anywhere I go.

Thanks
Duane
96 Sahara 30', 250hp Cat 3126
Allison 6spd MD-3060
2015 Jeep Cherokee Trailhawk "Toad"
Spokane WA
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Exhaust Brake 'Mode" in the "Cruise Control Perimeters"

Post by TDJohn »

05wingrider wrote: Wed Dec 04, 2019 7:26 pm Brett,
You state that you have yours set to 5th and are able to use the up/down arrows to change your gear as necessary - is that something that is available to any of the Allison transmissions? Mine is set to 2, but I noticed that there doesn't seem to be any changes allowed (I tried using the arrows last time going down a hill with no change). I think at this point that I'd rather have mine set to 5th for long grades since I'm in the PNW and have hills anywhere I go.

Thanks
Duane,

What ever pre-select gear is programed in the Allison transmission, you can't override the pre-selected gear by trying to use the up arrow to shift upwards, while the exhaust brake is activated. You can only shift further down. Since you do mostly mountain driving, your best bet would be to have Allison reprogram your transmission's pre-select to 5th, just like Brett has. This way you can opt to shift further down if you need more braking power.

Someday, when I have enough time and ambition, I will customize my Pac Brake where it will work with the pre-select and also without pre-select. This way I will have the best of both worlds. Selective mountain braking and also maximum braking for city traffic stopping power. I will be able to do this easily because my Cummins Engine is a mechanical engine and thus the Pac Brake is activated by a simple foot switch. I will just install a second foot switch and run it directly to the Pac Brake, via a relay, to prevent any back feeding to the Allison computer.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
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