Ok, I have been doing a lot of research as to the need to regear my 2012 wrangler unlimited when I get my lift and 35s. It is a standard with stock steelies (I know I know. The reason I want the 35s. I hate the roller skates). So with everything out there I asked the parts guy if I should regear. After speaking with him he let me know that the whole process is done by connecting a box to the jeep computer and setting it for the tire size. I asked him again to be sure that a regear would assist the fuel scone my and so forth. Is this really the process or is it simply to help the computer recognize the tires and tires and adjust the sleek. Someone let me know because I would hate to get 35s and then find ou I need to regear 1200 buck vs this box which is 50-60. Thanks !!!

 

Sorry about the typos. Damn phone.

 

35" with 3.21's is going to be a dog. I have 3.21's and 32" tires on my 2013 jku and no way no how would I want 35" with 3.21's. It s fine with 32" but that is about as big as you want to go with 3.21's.

 

Agreed. Regear is a must for me. 33's and 321 sucks!

 

You will need to regear.

 

The box that he is talking about is only going to correct your speedometer and odometer.

When you put larger tires on your JK the performance will suffer. Doing a re-gear will give you back that performance but it will not be cheap like that box.

On my 2011 JK (which has a joke of an engine IMO) I have 33's, 6th gear is almost useless on the highway. If I had 35's I would not be able to use 6th gear at all.

Once I need tires again I will be installing 35's but at that point I will have 4.88 gears and ARB Air Lockers.

I hope I helped clear this up for you.

 

LOL. Please ask the parts guy where can we get this magical black box that changes out differential gears.

I can't believe they employ such clueless people

 

Regearing is changing your gears from 3.21 to a more suitable gear; be it 4.56 or 4.88 or 5.13 or 5.38 depending on your future plans.

When they "regear", they open up your axles at the pumpkin, take the gears that are in there out, and put in new ones.

It takes a ton of minute work and is time consuming, which is why it costs so much.

That little box, will just correct your speedo and tire pressure for TPMS. A Procal or SuperChips would be preferred so you can have more options, like driving lights and rpm range for winching and others.

 

Short answer: You will need to re gear,, You will need Pro Cal.

 

I have a 2012 with a 6 speed, 3.21 gears and 35s. I keep it in 5th and I get an average of 18-19 mph. On the Interstate 70mph+ in 6th I get the same. I'm fine for now, but I also never plan on rock crawling. Playing in the mud/snow I'm fine. For anything else I have 4wheel Low.