Upgrading gear ratio from 3.42 to 4.10

[Jfloyd1112]

    I’m planning on upgrading my gear ratio from 3.42 to 4.10 on my 2019 custom trail boss. I want to put a 4-6 lift on my truck from BDS with fox shock coilovers With 35 inch tires maybe 37’s but before that I want to regear my truck so that I don’t lose any power. Do y’all think 4.10 gears are good enough for should I go for like 4.55’s? If anyone has re geared there 2019’s and up please let me know the prices and gear shifting experiences.

[CamGTP]

With the 6 speed auto you'd more than likely want 4.10's at a minimum with those large/heavy tires.

 

The downside you face is that to tune the computer for the gear ratio change and to make the transmission shift properly again you have to spend a ton of money just to tune it. The minimum cost is about $1,900 if you already owned the tuner device/software.

[f8l vnm]

how much is parts/labor ? 

From what ive heard this is very expensive? 

[AJMBLAZER]

Parts are many hundreds of dollars depending on if you need bearings, races, seals, etc. 

 

Labor ranges from a couple hundred and beer (you know a guy) to over a grand (shop prices).

[greco2003]

I didn’t think the transmission computer was unlocked yet? I know they got the truck computer but in that thread last I looked they said the transmission computer wasn’t unlocked yet.

[AJMBLAZER]

Transmission doesn’t matter. As long as the signal is corrected for the actual wheel speed after tire and gearing changes it sees nothing different. 

[Grumpy Bear]

2 hours ago, AJMBLAZER said:

Transmission doesn’t matter. As long as the signal is corrected for the actual wheel speed after tire and gearing changes it sees nothing different. 

For that matter if the gear and tire as a combination are within a few percent of OEM it's good. 

[AJMBLAZER]

True but that’s not super common. Especially with GM traditionally being high geared stock. 

[flyingfool]

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Edited May 16, 2020 by flyingfool