Allison tranny
12-11-2006, 09:27 AM
#241
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Thanks, Aaron
12-11-2006, 11:14 AM
#242
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FYI - A few years ago I rented a Ford F650 water truck that was brand new and it had in it for a drivetrain a 24V 5.9 Cummins with a Ailison 1000 transmission. I'm preatty sure it was all stock. Plus, the Allison the Chevy's are running has the same bellhousing bolt pattern that all GM trans have ie; TH350, TH400, 700R4, 4l60E, 4L80E. In the Chevy's that I've seen with the Allison, the trans have a standalone computer, meaning it's separate from the engine computer. I'm sure there are inputs to the engine computer that tranfer to the trans computer. For what it's worth.
12-11-2006, 12:27 PM
#243
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The F650 runs an allison 2000 series behind it.
12-13-2006, 01:03 PM
#247
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after talking with several knowledgeable people, I was definetly half wrong.
Yes it will shift without SEM, but it will shift like crap. So if you are running a calibration that uses purely TPS and nothing else, it is NOT going to shift nice as a daily driver, or like the GM HD pickups that use SEM. Same calibration a school bus or garbage truck uses, I understand those run only on TPS with no SEM.I will refuse to beleive you can make an allison 1000 shift nice without SEM/data from the engine computer. Why are HP rating inputs so much higher when the TCM uses SEM? It would be MUCH MUCH easier to destroy an allison running big HP and no SEM.
hard shifts on an allison are NOT good. If your allison shifts really hard you are getting tie ups for a split second and you WILL break things. With huge power running thru it and no SEM, the trans/trim solenoids can not react fast enough to trim on the required clutchpakcs and simualtaniously trim off the other clutchpacks without flaring the shifts (not fast enough) OR getting a tie up (too fast). Especially during the 3-4 shift, a hard 3-4 is deadly because you are transitioning from a combo of one rotating clutchpack and one stationary to using a combo of the two rotating clutches. I think thats why its so hard, I could be wrong. That is a very tricky hand off for the trans to make, and almost impossible with big power and no SEM. At some point during the shift you will have 3 clutches applied at once and I think it will tear apart the P2 planetary hub...or maybe the C2 drum splines I forget.
Maybe it will be possible when allison changes from the current PWM solenoids to the new VBS solenoids (variable bleed solenoids) but I dont know nearly enough about the trans to say whether that will make a difference or not
ben
12-14-2006, 07:01 AM
#248
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You obviously aren't talking to very knowledgeable. You DO NOT need SEM to shift good. My truck shifts super smooth. SEM is not needed in all applications. I will tell you once again, it is all in the programming. I have over 20,000 miles on my truck. I guess my tranny should have imploded by now, right? So you are telling me that all trucks that have an allison have SEM? They don't.
12-14-2006, 01:43 PM
#250
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the person I talked to probably knows more about the LCT and how to make it work in non-standard applications (racing, high power, etc) than the allison engineers themselves.
I still think your truck shifts nice becuase you do infact have it interfacing with the cummins ECM. Set it up on a 12valve and post a video of the shifting and then I will beleive you.
Why didnt you post a pin-out of YOUR TCM connectors?
I know a couple people who have done cummins/allison conversions. They all shift nice. They are also all interfacing with the cummins ECM to do so.
I still think your truck shifts nice becuase you do infact have it interfacing with the cummins ECM. Set it up on a 12valve and post a video of the shifting and then I will beleive you.
Why didnt you post a pin-out of YOUR TCM connectors?I know a couple people who have done cummins/allison conversions. They all shift nice. They are also all interfacing with the cummins ECM to do so.
12-14-2006, 02:16 PM
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obviously the person you talked thought they knew more about making it work in other applications, but they don't. I don't know how many times I have to tell that it doesn't interface with the ECM. There has already been a 12 valve done. I don't understand what would make the difference if it was. It is running TPS voltage off the engine and that is all. I am not going to just give you all my pinout locations. I don't feel that I have to prove to you that it works. You need to step outside the duramax box.
12-14-2006, 03:29 PM
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12-14-2006, 10:28 PM
#255
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Lets not get into a who knows more battle. I wanna see this thread go with more info and not 2 fighting over it cant be done with someone who did it and is going to do it for more ppl. I Cant wait till some of these guys thinking about doing the conversion do it and come back with thier report. Gabe keep up the good work and dont stoop to the level duratothemax is at.