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Topic: Transmission reprogram for preselect downshift (Read 525 times) previous topic - next topic

Transmission reprogram for preselect downshift

Hello,
I went to have my transmission reprogrammed so that upon Jake Brake activation the trans would down shift to fifth instead of fourth. It should have been a simple change of the customer installed configuration parameters but the tech was unable to see any of them. The final consensus was that a password was needed to access the parameters because the program kept asking for a password. The standard Allison default passwords had no effect. After an hour of putzing around with different passwords etc. I called off the effort.  I called the factory and they were unaware of any unique password used.
I am now thinking of separating the jake from the trans to have better control. Any thoughts?
Thanks,
Rick
P.S.  W.W. Williams in Tucson was very professional and accomodating and I believe they did everything they could.  I would use them for other services if needed. I asked to pay them the hour labor they spent on it but they refused and would not take anything.
Rick

Re: Transmission reprogram for preselect downshift

Reply #1 –
Guess a call to "Mother" Allison is in order with your transmission and ECM serial numbers.

Sorry, my phone directory is not on this computer.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Transmission reprogram for preselect downshift

Reply #2 –
There seems to be a disconnect between theJake Brake & Allison, our local vol. fire dept. has a DDC 50 Series Allison 3000 auto with 5 speeds, when you hit the brake pedal while on or near the rev limiter, it goes from 5th to 3rd right now, over reving the engine damage valve train, only solution, turn the Jake OFF until you slow down OR stand on the brakes HARD, not what I call a brilliant setup.  The local DDC factory shop seems clueless and/or uninterested.  Has been towed to the DDC SHOP 3 times so far :o
I am certain we two are not alone.
Dave M

Re: Transmission reprogram for preselect downshift

Reply #3 –
Quote from: wolfe10 –
Guess a call to "Mother" Allison is in order with your transmission and ECM serial numbers.

Sorry, my phone directory is not on this computer.
Brett,
The Williams tech had placed a call to Allison but we did not get into serial numbers etc. although I offered all of the info up front. As the first hour was coming up I could see that several hours could have been spent to get a solution so I called it off. I guess I will contact Allison directly and try to bring better info to the next technician. 
Thanks,
Rick

Dave,
The Jake and the Allison (HD4060) work well together on my coach and works as follows;
    *  while cruising in 6th gear and wanting to slow down you flip the Jake switch on (cruise control OFF)
    *  if over 58 mph the trans will stay in 6th and Jake brake will not activate
    *  you have to get the coach down to 58 mph, then the trans will downshift to 4th, revs come up to 2050 or so (red line          for my engine with the Jake) and then the Jake brake will kick on full
    * if you are on a very steep grade you may have to apply some foot braking (rarely) to keep the revs at red line (max braking effect)
    * It will NOT downshift to 4th until the mph is 58 mph which will bring the revs to red line.
    * ONCE YOU ACTIVATE THE JAKE AND IT COMES ON IN 4th, IT WILL STAY IN 4th AND YOU CAN OVER REV THE ENGINE IF YOU ALLOW THE RIG TO ACCELERATE DOWNHILL!! If you turn the Jake OFF (this can be done with the switch or the throttle pedal), the trans will immediately upshift to 6th and the revs will drop. If you turn the Jake off by either method and get the trans upshift to 6th then the transmission will not downshift to 4th until you get the rig down to 58 mph again.
   
I like to cruise around 62 mph and sometimes on a long somewhat shallow grade the rig will go to 75+ without foot braking and if I activate the Jake (less than 58 mph) ahead of the long grade I have to keep touching the throttle pedal to keep control of the Jake, mph, and RPM's. This will shift the trans back and forth several times before the end of the grade while descending at a snails pace.

The tech at Williams took me back into the shop where he had a fire truck with a similar set up to mine. He plugged in to the trans ECM and entered into the programming mode, once there he showed me the parameters that were available for change. One of the several parameters was the preselect on activation of the Jake (known by a certain wire #). When viewing my ECM none of the changeable parameters were shown and the computer was asking for a password. The tech made a quick call to Allison but we all thought this would be a 10 minute change and as it dragged out I had to call it off. I am sure they could have figured it out but until I am at another stop for a couple of weeks the change is on hold.

My change is going to be one for my convenience not one to protect the engine although what I am asking the trans and Jake to do will not jeopordize the engine. As I mentioned earlier my Jake and Allison are talking to each other OK I just want to hear a different story. Sounds like your VFD has a different issue.
Good luck,
Rick

Rick
 

Re: Transmission reprogram for preselect downshift

Reply #4 –
Makes me appreciate the Retarder more, My world has no future for a Jake!
If you have the Jake with the manual gearbox, you have control.
My feeling for an auto trans with Jake Brake, is the same as putting lipstick on a pig.
Dave M