2012 Unlimited with 35" and stock 3.21. Do i need to regear and how much it may cost? - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 07-26-2012, 08:18 AM   #1
Jeeper
 
mallaki's Avatar
 
Join Date: Jun 2012
Location: Queens, NY
Posts: 273
2012 Unlimited with 35" and stock 3.21. Do i need to regear and how much it may cost?

Hello,

I have 2012 JK Unlimited Auto with 3.21 gearing. I have opted for 35” tires that were installed by dealer right on spot when I was buying my jeep. I was told he has installed some spacers, so 35”s will fit. I am looking into lift right now and already have one in mind. Thanks to folks like you on this forum.
Now, my other concern is, since I have upgraded to 35” BFGoodrich Mud-Terrain T/A, do I need to regear??? If so, should I go to 3.75 or higher??
I have put close to a 1k miles so far and the mileage in the city is about 12miles from gallon. On the highway, between Harrisburg and NYC (some traffic but not a lot) a got average of 17.1 miles out of a gallon. If I would to regear to 3.75, would that help my mileage or actually make it worse???
Also, what am I looking at in cost. I understand I have to regear front and back. What is the cost I could expect to have the whole job done A to Z by dealer or local shop. I live in NYC (Queens)

Thank you all very much

mallaki is offline   Quote Quick Reply
Old 07-26-2012, 09:40 AM   #2
Jeeper
 
dprimm's Avatar
 
Join Date: May 2012
Posts: 215
I am sure someone with real knowledge will chime in soon. Expect the cost of the re-gear to be between $1500-$2000 parts and labor (dealer will cost more). The regear will help with both accelleration and gas mileage I believe. You also will want to invest in an AEV Procal moduel ($150) so you can correct the factory computer settings to recognize the bigger tires and new gears.

dprimm is offline   Quote Quick Reply
Old 07-26-2012, 09:45 AM   #3
Jeeper
 
steve31's Avatar
 
Join Date: Mar 2012
Posts: 1,379
I got quoted at a dealership for the labor on the regear as 750 but you need to provide your own parts.
steve31 is offline   Quote Quick Reply
Old 07-26-2012, 10:46 AM   #4
Jeeper
 
mallaki's Avatar
 
Join Date: Jun 2012
Location: Queens, NY
Posts: 273
Quote:
Originally Posted by dprimm View Post
I am sure someone with real knowledge will chime in soon. Expect the cost of the re-gear to be between $1500-$2000 parts and labor (dealer will cost more). The regear will help with both accelleration and gas mileage I believe. You also will want to invest in an AEV Procal moduel ($150) so you can correct the factory computer settings to recognize the bigger tires and new gears.
Is this for front and rear? all parts and labor included??
mallaki is offline   Quote Quick Reply
Old 07-26-2012, 10:47 AM   #5
Jeeper
 
mallaki's Avatar
 
Join Date: Jun 2012
Location: Queens, NY
Posts: 273
Quote:
Originally Posted by steve31 View Post
I got quoted at a dealership for the labor on the regear as 750 but you need to provide your own parts.
was this for front and rear?
mallaki is offline   Quote Quick Reply
Old 07-26-2012, 10:56 AM   #6
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,116
For your 2012 Auto, 4.56 or 4.88 is reccommended for 35's. Buy parts from a vendor here. Jason at Krawl Off-Road, I got my 5.13's from him. You will need new carriers too. I didn't so don't know what the cost is on them. You can always get lockers too, which replace the OEM carrier.

$1500 - $2000 should be close, front and rear, parts and labor. (Not including the lockers of course)

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Rock Krawler package deals available
http://www.wranglerforum.com/f37/roc...ml#post9982953
Daniel_M is offline   Quote Quick Reply
Old 07-26-2012, 11:43 AM   #7
Jeeper
 
mallaki's Avatar
 
Join Date: Jun 2012
Location: Queens, NY
Posts: 273
Quote:
Originally Posted by Daniel_M View Post
For your 2012 Auto, 4.56 or 4.88 is reccommended for 35's. Buy parts from a vendor here. Jason at Krawl Off-Road, I got my 5.13's from him. You will need new carriers too. I didn't so don't know what the cost is on them. You can always get lockers too, which replace the OEM carrier.

$1500 - $2000 should be close, front and rear, parts and labor. (Not including the lockers of course)

-Dan
Hello Daniel,

If I choose to that high - 4.88 as you mentioned, I understand that it will improve power, how will that affect my mileage per gallon??.
I am and will use this Jeep most of the times for highway commute. Will do some light to moderate off-road every now and then. I really don’t have any complains as far the power goes with the Jeep. Of course I understand that 35” came with a price, but just looking for ways to make it better on average in all aspects. So, re-gearing it to 4.88 (power gain aside) how will that affect my gas usage??

Thanks
mallaki is offline   Quote Quick Reply
Old 07-26-2012, 12:27 PM   #8
Supporting Member

WF Supporting Member
 
JeepHerz's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 2,353
Images: 20
Similiar to above: I was quoted $900-$1500 for front and rear- to 4.56s or 4.88s A new tire carrier is around $300-$700. As with all things Jeep- there are a ton of options so the price varies wildly.
Just a word of caution- there really is no way for anyone to tell you what your gas mileage will be. It will vary wildly depending on how you drive. You can look at the gear charts and the "green" all day long but there is no guarantee. If you're fine with the power now- why spend $1500? That's a lot of gas money.
JeepHerz is offline   Quote Quick Reply
Old 07-26-2012, 12:40 PM   #9
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,116
Quote:
Originally Posted by mallaki View Post
Hello Daniel,

If I choose to that high - 4.88 as you mentioned, I understand that it will improve power, how will that affect my mileage per gallon??.
I am and will use this Jeep most of the times for highway commute. Will do some light to moderate off-road every now and then. I really don’t have any complains as far the power goes with the Jeep. Of course I understand that 35” came with a price, but just looking for ways to make it better on average in all aspects. So, re-gearing it to 4.88 (power gain aside) how will that affect my gas usage??

Thanks
I believe you would be in the “green” for both 4.56 and 4.88’s but your mileage would probably be better with 4.56. 4.88’s on a 2012, you’d be set up for 37’s in the future. And as Jeepherz said, if you are ok with it now then why regear? People’s tolerance levels with the gearing and big tires vary widely.

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Rock Krawler package deals available
http://www.wranglerforum.com/f37/roc...ml#post9982953
Daniel_M is offline   Quote Quick Reply
Old 07-26-2012, 12:47 PM   #10
Jeeper
 
MikeK46's Avatar
 
Join Date: Mar 2012
Location: Long Island, NY
Posts: 1,623
Images: 4
In my opinion your gas mileage will improve with the new gears, since you won't have to mash the gas so hard anymore to get the truck moving
__________________
12JK
MikeK46 is offline   Quote Quick Reply
Old 07-26-2012, 03:47 PM   #11
Jeeper
 
mallaki's Avatar
 
Join Date: Jun 2012
Location: Queens, NY
Posts: 273
Thank you all for your responses.

I am not necessarily looking to re-gear. I was told on several occasion that I should re-gear as it will improve many things. Not sure what things it will improve. I know it would increase power, however as I mentioned before, I’m ok with the power I have now.
Dealer told me that I don’t have to re-gear as 2012 is completely different animal than 2011 or earlier since new engine has been dropped in with approx. 80 more horsepower.

Since I have heard several different stories and I only have the stock lowest gear being 3.21, I was wandering, if maybe going to higher number will ease up transmition/engine work and therefore lower my average MPG. I understand that we all drive differently and it’s difficult to compare, but let’s just assume for argument sake that I would drive identically with different gears (3.21, 3.75, 4.56 or 4.88) and 35” wheels. Now having that in mind, which one would benefit me the most as for MPG. I as said before 90% or more of my rides are on the highway and city traffic.

Thanks again !!
mallaki is offline   Quote Quick Reply
Old 07-26-2012, 03:55 PM   #12
Jeeper
 
mallaki's Avatar
 
Join Date: Jun 2012
Location: Queens, NY
Posts: 273
Quote:
Originally Posted by Daniel_M View Post
For your 2012 Auto, 4.56 or 4.88 is reccommended for 35's. Buy parts from a vendor here. Jason at Krawl Off-Road, I got my 5.13's from him. You will need new carriers too. I didn't so don't know what the cost is on them. You can always get lockers too, which replace the OEM carrier.

$1500 - $2000 should be close, front and rear, parts and labor. (Not including the lockers of course)

-Dan
Daniel,

What do you mean by "You will need new carriers too"

What is a carrier??

Thanks
mallaki is offline   Quote Quick Reply
Old 07-26-2012, 03:55 PM   #13
Jeeper
 
mallaki's Avatar
 
Join Date: Jun 2012
Location: Queens, NY
Posts: 273
Quote:
Originally Posted by Daniel_M View Post
For your 2012 Auto, 4.56 or 4.88 is reccommended for 35's. Buy parts from a vendor here. Jason at Krawl Off-Road, I got my 5.13's from him. You will need new carriers too. I didn't so don't know what the cost is on them. You can always get lockers too, which replace the OEM carrier.

$1500 - $2000 should be close, front and rear, parts and labor. (Not including the lockers of course)

-Dan
Daniel,

What do you mean by "You will need new carriers too"

What is a carrier??

Thanks
mallaki is offline   Quote Quick Reply
Old 07-26-2012, 04:00 PM   #14
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,116
Regear doesn’t increase power, it puts what you have down to the ground more effectively. Making up for the revolutions required to turn bigger tires.

Dealer is correct in saying that the 2012 is different but stating that you DO NOT need to ever re-gear a 2012. True you don’t NEED to but if you do, your vehicle will drive more efficiently. Much like when it was brand spakin’ new. In your case 4.56 will suit you best, IMO.

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Rock Krawler package deals available
http://www.wranglerforum.com/f37/roc...ml#post9982953
Daniel_M is offline   Quote Quick Reply
Old 07-26-2012, 04:07 PM   #15
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,116
Quote:
Originally Posted by mallaki View Post
Daniel,

What do you mean by "You will need new carriers too"

What is a carrier??

Thanks
A carrier is a case that carries your gear set inside the diff. The 3.21’s carrier are different from the 3.73 and numerically higher ones. I don’t know why or how but they are. Anyone re-gearing from 3.21 and staying open will need replacement carriers. If you are adding lockers and re-gearing, the lockers (depending on which ones you get) will come with a new carrier.

I am no tech or mechanic so don’t know the technical specs. Just a DIY wrencher.

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Rock Krawler package deals available
http://www.wranglerforum.com/f37/roc...ml#post9982953
Daniel_M is offline   Quote Quick Reply
Old 07-26-2012, 04:08 PM   #16
Jeeper
 
BakedInMN's Avatar
 
Join Date: May 2012
Location: St Paul Minnesota
Posts: 245
I assume he means the Carrier Bearings.
__________________
"You're more awesome than a monkey wearing a tuxedo made out of bacon riding a cyborg unicorn with a lightsaber for the horn on the tip of a space shuttle closing in on Mars while engulfed in flames."
BakedInMN is offline   Quote Quick Reply
Old 07-26-2012, 04:13 PM   #17
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,116
Quote:
Originally Posted by BakedInMN View Post
I assume he means the Carrier Bearings.
Pretty sure carrier bearings will be included in a master installation kit as included in the price of the parts. The carrier I think is a separate purchase.

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Rock Krawler package deals available
http://www.wranglerforum.com/f37/roc...ml#post9982953
Daniel_M is offline   Quote Quick Reply
Old 07-26-2012, 04:14 PM   #18
Supporting Member

WF Supporting Member
 
JeepHerz's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 2,353
Images: 20
Deleting my own post...

JeepHerz is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 04:54 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC