This is gonna sound super stupid and blow everyone's mind , but I do not understand torque converter lock up as in what it dose why it dose it the benefit of it the whole shabang I have read and googled and searched slept on top of text books hoping for the osmosis effect but for whatever reason transmission and torque converters are witch craft and wizardry, that being said I see lots of people getting the alli locker and other manual lock up devices and want to know more about it so I can make the decision on if maybe I need/want one or not. So what I'm asking is for someone to break it down to me in the simplest of ways, like the KISS method took Barney by the tail and beat me in the head simple. Thanks and sorry to make your brains hurt with this.
I think lockup is the easiest part to understand in the whole Torque Converter conversation. In the most simplest explanation, the torque converter ceases being a fluid coupling between the engine and the transmission, and locks it's input/output to directly connect the engine and trans. The act itself is simple, but when you start making power beyond stock and have a stronger converter, acceptable controlling of this function becomes difficult for the Allison software to handle. The Allison tries to protect the torque converter as though it is the stock unit and not a robust aftermarket unit capable of locking up even where there's slip that would be detrimental to the factory parts. We add the lockbox to force the application of lockup when it isn't happening to our satisfaction otherwise. The box is also used to force an unlock when needed by pullers in competition at the end of their run (as I understand it; no direct experience there).
