New Jake brake

[mpwalker]

Can someone please tell me why the new Jake brake being touted by Cummins and Dodge will work with the 2006 Auto transmission but not with the 2005 transmission? I am not a mechanic and do not understand this question since a dealer told me that when it came to engine and transmission there was no difference between my 2005 and the 2006. Sure would like the brake on my 2005, 3500, cummins but it appears I will not get one but do not understand why. Thanks for the feedback.

 

[ohnoitsyu]

Yes.

https://www.turbodieselregister.com/forums/search.php?searchid=850024

 

[klenger]

In short, the 2005 ECM software does not support the exhaust brake. The transmission hardware does support it. If I am wrong with my comments, someone is sure to correct me.

 

[mpwalker]

Wow I sure learned a lot today, more than I wanted about the Exhaust Brake, thanks for the feedback. We are fulltime Rvers and went to the local dodge dealer for recall on front springs on our 2005, 3500, cummins auto transmission with 36,000+ miles on it, while there getting an appointment was told by parts people that they could put the "new Jacobs Exhaust brake on for me" something I have wanted due to our pulling a heavy 5iver in the mountains, so told them to go ahead. Today they call me (have had the truck for 2 days, still no new springs)tell the brake is installed but will not work, since they have now found out that is is not for 2005 auto transmission. Now have an exhaust brake installed that will not work (they read the part number information wrong 2004. 5-2006 instead of 2004. 5 "and" 2006 auto transmission), however the diesel machanic says he can get it to work with some wiring changes that will not affect the engine, however we will have to work it "manually". Other option is to have them remove it, either way from the way the service manager talks they plan a big fight over who pays for the parts since they claim they cannot send it back since it has been installed. One more option I came up with after reading all the post here is to leave it on and wait for the software upgrades to come out for the 2005. I am not a machanic so do not fully understand what all my options may be here, any feedback from TDR members would be most appreciated.

 

[BHolm]

I was first going to tell you to just go for it and run it manually. As I was typing it occured to me that this might not be the best route. For the brake to work without toasting the trans the convertor needs to be locked. In tow/haul mode you "should" be OK. That will keep the convertor locked and you can run the brake. The problem comes when downshifting. On the '06 the electronics actually shut the brake off, unlock, downshift, re-lock, and re-engage the brake. That is going to be tough to verify manually. You would have to manually release the brake and re-engage it after the downshift and convertor lock. Can be done, you would just have to be careful. The new electronics also allow the brake to be on when the cruise is set and the computer will automatically use the brake if you start rolling downhill.



I know you can get a locked TC in T/H coming downhill in 4th, 3rd, and 2nd with the '05. If you decide to allow them to override it to a manually activated feature, the trans is in your hands. I would have a trans temp gauge as mandatory. The '06 would have a fail-safe mode if the TC didn't re-lock after a downshift, you would not.



Since it is installed I personally would have it overridden and use it carefully. I would also start putting pressure on DC to release a software update for your truck. Sure makes it slick when the electronics are so well integrated.

 

[jelag]

BD and PacBrake offer kits that will modify the transmission, and allow you to use your new exhaust brake... .



What the kit does is hold up the fluid pressure in the transmission during de-acceleration... this higher pressure keeps the fluid from overheating in the torque converter and allows the power from the rear wheels to be absorbed by the engine...



For more information on the e-mail me at -- email address removed --... I'm out of town... on business and won't be back until Monday... but I can get the information than and quote you. . or go to www.PacBrake.com for the basic information... .