Transgo 1-2 Shift

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Jan 6, 2013
Golden, CO
After my supercharger install I want to try to fix some of the flare I'm getting in my shifts, especially accelerating onto the highway. I got the Transgo 340-HD2 reprogramming kit like a few others have. I haven't installed yet, but will drill it for "truck". The one complaint I've seen with that kit is a hard 1-2 shift. That has me wondering if I can not enlarge the 1-2 port to minimize that. Either that or drill it out less than what they specify with the "truck" settings. Anyone know if that will cause problems?
Its not much. WOT merging onto the hwy usually. I don't think my transmission was well cared for in its previous miles.
Interesting idea. Seems like it would work ok. I bet you could just ask at a transmission shop to see what they think, or email Transgo. Mine is done on the high performance setting (whatever they called it) and it does shift pretty hard, but i don't hate it or anything.
The only thing you are doing when you drill the holes out is increasing the pressure. If you want less pressure drill a smaller hole, it isn't rocket science, and I think on the truck setting you will be totally fine. I did mine on the hot rod setting and even it is not like teeth chattering on the 1-2 shift even in low range.
Hole size has nothing to do with overall pressure. It's the rate that Pressure is applied. I think the 1-2 shift is to hard and if I would do it again I would not drill it out. The Increased size increases the flow for a quick shift. My situation is a little different than most but. 1-2 is very agressive and have to short shift it to not feel like I'm cracking gears.

On the same note I can control the shift point with my standalone and short shift 2nd under normal driving. At full load the firm quick shift is nice and prabbaly leads to less clutch wear and the shift deals great. But I'm talking about 200hp+ and close to 500 ft lbs at lower rpm than most are dealing with
A friend of mine did this in the A343F in his Hilux Surf. Same comments regarding the 1-2 shift, in that he wouldn't do it again (I would agree having driven it).
Yeah I don't know what most people are having an issue with. I drilled the biggest hole (hot rod) I used the heaviest springs for the accumulators and the pressure regulator, and the 1-2 shift is not that bad. I daily drove my truck for months without giving it a second thought. I will get a video of it today. I have absolutely zero issue with any of the shifts being too hard and worrying about cracking gears. They are not even all that firm, but they are positive without flaring under heavy throttle. In my opinion the difference after doing the shift kit compared to before doing it is night and day and how the transmission should feel.

And I am not recommending you do this but I can't see how the truck settings could be that upsetting....
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