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Jacobs Brake

Yahoo Message Number: 67494
Hi All,

My coach is a 2007 Allure with the Cummins ISL. My jake brake is set at factory settings but here is my question. I am a former truck driver and with a manual transmission I chose my shift points even as I was descending a grade. It seems that with the Allison and the Jake on it continues to shift down. Have any of you reset your Jake brake via the Allison controller to have full control of the gear and when the Jake Brake is activated.

Thank you for your responses.

David

07 CC Allure Siskyou Summit

Re: Jacobs Brake

Reply #1 –
Yahoo Message Number: 67498
As originally programmed my transmission automatically downshifted to 4th immediately when the jake brake was applied. This resulted sometimes in a pretty harsh shift so on an early visit to local DD/Allison facility I talked to the transmission man and he said it was a relatively simple matter to turn off this "feature" and did so at no charge in only a few minutes time accessing the transmission control module close to the selector switched to the left of the driver. Now, my jake brake activation has no effect on the transmission except, of course, that as speed decreases the transmission downshifts just the same as if the jake wasn't on. When approaching a situation (long descent, etc.) where I anticipate using the jake I usually downshift, say to 5th, and let the gearing slow me a little before applying the jake. Anyway it's a lot more flexible than as originally programmed. It also means I can use the jake in 6th for a relatively light retard effect if that's all I want. It also smooths things out if I'm driving in a situation where I want to leave the jake "on" and control the activation with the throttle - like fast moving Denver freeway traffic.

Jim M

'02 Intrigue #11410 ISL 400

Re: Jacobs Brake

Reply #2 –
Yahoo Message Number: 67502

The 2nd stage of my Jacobs brake no longer functions , The Cummins guys say it is fine on the engine side and that I may have a wiring problem . I wonder if it is something simple , does anyone know of a socal shop or someone that I might use to get into the details.
Jim Polk

07 Allure 470

Re: Jacobs Brake

Reply #3 –
Yahoo Message Number: 67505
Where are you??

We had a similar problem and it was a Cummins issue. The Cummins NW shop in Coburg did a great job for us.

Jim

07 Allure #31570

Re: Jacobs Brake

Reply #4 –
Yahoo Message Number: 67508

thanks for the tip, I have had it to Cummins twice with no luck, I'll call the Coburg shop and ask for advice.

Re: Jacobs Brake

Reply #5 –
Yahoo Message Number: 67520
When I purchased our coach and took delivery at the factory I had Gary change my tranny to select 3rd as I drive a lot in the mountains of Colorado and out west. Later on I had it automatically select 2nd. When you are navigating narrow roads with sharp turns in California and on a particular trip in West Virginia you don't have time to be playing with a touch pad. But that's been my experience. Take the short cut from Stanton, Virginia to Cass West Virginia and you will see what I mean. TWI 2004 Intrigue 42' 11731

Re: Jacobs Brake

Reply #6 –
Yahoo Message Number: 67548
Jim,

Thank you for the information. I am due for a service and I use Cummins West in California who is also an Allison shop. I will have my jake reprogrammed at that time. Thanks for the information.

David