Help adding lockup in 2nd

[08Z71]

im new to the whole tuning scene but my dad is an allison tech and we're trying to force the trans into lockup in second. Apparently commercial allys are in direct drive from 2nd to 6th. Im tryin to improve fuel economy basically. Has anyone done this and where do i even start? :help:

[THEFERMANATOR]

tow/haul mode locks the converter in 2nd on up. Locking the converter won't neccesarily help milage out either. And I haven't tried it on a 6 speed, but on a 5 speed it doesn't work so well trying to make it lockup in 2nd and hold it as we don't have access to the 0% throttle lockup tables in EFILIVE.

[08Z71]

I hav the 6 speed A40 allison and i do have access to 0% throttle tables in efi live. How would i go about forcing 2-4 into lockup. Lockup comes in in 4th stock anyway.

[THEFERMANATOR]

The tables go to 0% in the 5 speed tables same as in a 6 speed, but I have found there is another table that isn't present that controls lockup at 0% throttle sort of like how there is a seperate table that controls lockup at WOT even though the normal table goes up to 100%. I haven't verified this in a 6 speed, but in a 5 speed there is definately an issue. Also they don't normally go into lockup in normal mode as everytime you let off the throttle while in lockup you will get engine braking whereas without lockup it will coast. This will actually cost you milage around town having to give it throttle where you could normally coast before. The other option is to let it unlock at 0% throttle, but the TCM will prevent it from locking back up right away when you get back on the throttle again.

[killerbee]

The only contol issue we have not been able to work around, is the 600 rpm slip limitation. You won't get any lockup, in any gear until slip is under 600. Have not confirmed if this is also the same issue on the 6-speed.

[THEFERMANATOR]

The only contol issue we have not been able to work around, is the 600 rpm slip limitation. You won't get any lockup, in any gear until slip is under 600. Have not confirmed if this is also the same issue on the 6-speed.

The 600RPM slip limit is a problem in all controllers. And the 0% lockup I know is an issue with 5 speeds as it bugs the heck out of me losing lockup below 55 everytime I let off the throttle, then locks back up when I get on the throttle again.

[killerbee]

losing lockup below 55 everytime I let off the throttle,

You are refering to normal mode only??

It's been awhile since I worked this issue, what are your 0 throttle "apply" speeds of D5012 and D5013? Tried increasing these?

[THEFERMANATOR]

I've tried all of those and then some. There has to be a 0% table sort of like the WOT table to control lockup below about 7% throttle I have found. And yes it is only in normal mode. Most don't notice it as they don't try to lower 5th gear lockup speeds, but for me not getting lockup until 55 sucked with my 3.42 gears.

[KB3MMX]

I can mod your tcm tune and you can look at what I did to get lockup at around 22mph.
It doesn't unlock at 0% throttle either....great if you run a turbobrake tune..
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