Changing gears will not put a 3.6 into limp mode. The programmers like the AEV ProCal only change the speedometer. In an automatic, that change affects when the computer decides to shift.

 

Well there are a couple of exceptions.....you change the gearing on the transfer case. You swap and go from 2.72 to 4:1 you'll need the ProCal or similar device.

The ProCal also re-adjusts for auto tranny shift points as you do a differential re-gear.



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Okay I'm confused now. Will my Jeep go into limp mode when I change the gears? And a week later the tires?

 

Or can I get away without it for a month or so?

 

Okay well just talked to the guy at northridge4x4 he said he would recommend reprogramming but is doesn't always mess up. Want to give a big shoutout to those guys great customer service and very knowledgeable it sounds like! First time using them for part but this won't be my last! And thanks to everyone who has tried to help me out! Gotta love the Jeep community!

 

Lots of info on the subject.. I guess it doesn't happen all the time but who wants to take the chance..

Warning: Regearing 2012 Jeep Wrangler Causes Transmission Error

 

You don't need it right away but it allows you to change the gearing & tire size. This will change your shift points improving your jeeps drivability.

 

Gears are installed! Rolling on 33" until tomorrow when the 37" come in.
Right now love the gears on these 33".

Here's what everything cost me for those who are thinking of changing gears
$710 for labor
$91.17 Royal Purple fluid
$74.93 front Dana 30 carrier
$639.70 for front and rear 5.13 revolution gears and rebuild kit

 

Odd. In my 2014 3.6L automatic I got about 20 feet out of the garage and into the driveway before the thing went into hard core limp mode. That was after gearing/tire changes. Applied the Superchips Flashcal F5 to it and never had another issue.

 

Update... now have 37" on and 5.13 gears installed! Been driving for a day now and no limp mode so far!