D5072 table

[mitchd]

Hey guys, below are some pics of other transmission TCC Lock Rate tables, Can anybody tell me why the Allison table is totally different than the others? Why would they give more pressure at less slip on an application with double the stock torque of a gas engine?

I Have a Theory, but I want to see if anybody else can figured it out.



-Hint- The Allison controller is a Learning computer

[GMC-2002-Dmax]

To my knowledge the TCM on a AL5 controller is not in charge of ramping up any pressure via programming, it uses a mechanical spring to regulate pressure and upon lockup it drops pressure via mechanical means by not applying as much pressure to help control heat, it was built for towing and was designed to drop pressure in lockup in 4th-5th gears to help with that task by design.

The stock TC is fairly tight, so slip speed vs lockup happens quite easily especially with stock power levels, add 250 RWHP and 500 Lbs/Tq and a looser TC for a big single or twins and you have an issue with stock programming, you can adjust the TCC ramp rate but that is electronically controlled by the TCM.

The only learning it does is how quickly it applies one clutch vs the one coming off with TAPS that can be preset and then learn over time, adaptive learning.

The LML has a different strategy then the 5 and 6 speed pre 2011 transmissions utilizes.

[mitchd]

Yep the base pressure is controlled by a spring, and does knockdown the pressure when the TCC is engaged (unless you modified the knockdown valve).

I do not believe that table is psi per second, but is target lock time based on slip vs torque. This is why there are TCC adapts that can be reset by the Allison doc software.

I have been chasing lock issues with my triple disk since i got it, it was to harsh down low. I could tried to tune that out by lowering the numbers in this table and I also raised the higher slip numbers to speed up lock at high slip ratios. This didn't seem to help part throttle lock as it would not lock smooth. I have been starting to think that my converter clutch has been going out as my lock firmness with 1100+ rpm slip has degraded over the past couple months and maxing out the table didn't help, it actually seemed to make it worse.

So to test my theory I set the whole table to 1 and went for a drive, the first time it locked it slid in as it had before, the second time a little faster and so on....after about 20 full throttle locks with 1100+ rpm slip when it locks it now breaks the tires loose in second gear as it did before. I have now gone back to a basically stock lockup table with the first two colums raised 10 points and the 600 rpm slip end of the table set to 1 in all colums, high slip lock is almost instant and part throttle lockup is so smooth you cant even feel it lock, the rpms just slowly drop. I will post a log later showing the different lock rates.

[DURAtotheMAX]

The only learning it does is how quickly it applies one clutch vs the one coming off with TAPS that can be preset and then learn over time, adaptive learning.

thats wrong tony.

TCC has its own set of adapts. You just cant reset them with efilive or Tech 2.

Ben

[GMC-2002-Dmax]

thats wrong tony.

TCC has its own set of adapts. You just cant reset them with efilive or Tech 2.

Ben

I never said the TCC had TAPS, I said the ramp rate was adjustable...........so I do know what I am talking about, obviously you should read more carefully, I never said anything about TCC adapts.

The question was regarding pressure, which as you well know is set mechanically

[DURAtotheMAX]

I never said the TCC had TAPS

it DOES have TAPS.......................you said it didnt and there was no adaptive learning on the TCC...only on the regular shifts. Thats incorrect. The TCC apply is self-learning/adaptive. Not many people know that though, because the only way to reset it is with DOC.

[GMC-2002-Dmax]

it DOES have TAPS.......................you said it didnt and there was no adaptive learning on the TCC...only on the regular shifts. Thats incorrect. The TCC apply is self-learning/adaptive. Not many people know that though, because the only way to reset it is with DOC.

Ok, You won't go back and read what I posted, I never said anything about TCC Taps, so fine, it has TAPS,

Happy ????????

You are right it has non-adjustable TAPS that we can't reset, even though I correctly stated the ramp on rate can be increased and that is all I said.

You own the thread now.........I'm just a tuner

[THEFERMANATOR]

Line pressure is static and not electronically controlled via the TCM until 2011, but the rest of the pressures are controlled via the TCM during a shift and based off of TAPS(unless you have a TRANSGO at which point once it reaches roughly 60 PSI on a trim valve it goes full line pressure). So main pressure is not adjustable, but that is only applied to the C1 clutches in 1st, 2nd, 3rd, and when you first go into 4th. At that point the E shift valve strokes and transfers full line pressure to the C2's for 4th, 5th, and 6th. The C3, C4, and C5 clutch packs always receive there fluid pressure from the trim valves(roughly 125 max with stock trim valves, and full line once it hits 60 with TRANSGO valves). The TCC is fed it's pressure via the TCC(F solenoid), and it controls ramp in rate. I know I need to adjust my D5072 some to help smooth out lockup some more at part throttle, and it would be nice if we could get the extra table scaling to get lockup with higher slippage without a lockup controller.

[cmitchell17]

Yep the base pressure is controlled by a spring, and does knockdown the pressure when the TCC is engaged (unless you modified the knockdown valve).

I do not believe that table is psi per second, but is target lock time based on slip vs torque. This is why there are TCC adapts that can be reset by the Allison doc software.

I have been chasing lock issues with my triple disk since i got it, it was to harsh down low. I could tried to tune that out by lowering the numbers in this table and I also raised the higher slip numbers to speed up lock at high slip ratios. This didn't seem to help part throttle lock as it would not lock smooth. I have been starting to think that my converter clutch has been going out as my lock firmness with 1100+ rpm slip has degraded over the past couple months and maxing out the table didn't help, it actually seemed to make it worse.

So to test my theory I set the whole table to 1 and went for a drive, the first time it locked it slid in as it had before, the second time a little faster and so on....after about 20 full throttle locks with 1100+ rpm slip when it locks it now breaks the tires loose in second gear as it did before. I have now gone back to a basically stock lockup table with the first two colums raised 10 points and the 600 rpm slip end of the table set to 1 in all colums, high slip lock is almost instant and part throttle lockup is so smooth you cant even feel it lock, the rpms just slowly drop. I will post a log later showing the different lock rates.

Are you saying the psi values are the inverse? So they have units of time, so the smaller the value the harsher the lockup? My unscientific testing feels like D5072 has no effect on anything, but Im too lazy to take logs and notes and do controlled studies I just flash a new tune and try it to see how it feels. Ive tried to smooth it out using the max and min duty cycle (which I guess is safe to do?) In the 0-25%tps which is the worst part I have set my max to be from about 6-15% and it will lock sometimes where you can't even feel it, but like you said the controller will learn to start locking harsher again after a few locks.

Is the problem with the mechanical side in that the controller in the TCM has reached the limits to reduce duty cycle? Or is the clutch capacity of a triple disk to much from the controller to adapt to? Also it seems like the TCM ignores the max duty cycle tables also because like I said my max is set to about 6 in some tps ranges and im seeing around 35% DC in the logs with no change in slip then it decides to lockup abruptly by just raising the duty cycle to around 40-50% which is way out of range of the limits I have defined in the max DC table??