4.88 or 5.13 gearing - 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 03-02-2012, 08:36 PM   #1
Jeeper
 
JKERS's Avatar
 
Join Date: Dec 2011
Posts: 51
4.88 or 5.13 gearing

I am ready to tackle the re-gearing of my rig, I am not sure whether to go with 4.88's or 5.13's in my '11 JKU, automatic trans, 35" tires......anyone with any experience or insight would be much appreciated.."..

JKERS is offline   Quote Quick Reply
Old 03-02-2012, 11:07 PM   #2
Jeeper
 
Yella's Avatar
 
Join Date: Jul 2011
Location: St. Peters, Missouri
Posts: 735
Quote:
Originally Posted by JKERS View Post
I am ready to tackle the re-gearing of my rig, I am not sure whether to go with 4.88's or 5.13's in my '11 JKU, automatic trans, 35" tires......anyone with any experience or insight would be much appreciated.."..
I know you want to regear but look at this thread started by PieFace who doesn't want to regear.

http://www.wranglerforum.com/f33/wan...ar-141613.html

Now this was a thead intended for 2012 but it has lots of info about regearing in general and for 2012, <2012, auto and manual.

__________________

2008 JK Sport, lightly modded.
Ordered for Mrs Yella: 2014 Sahara JKU, Amp'd, auto, hard top, leather, 430 nav connect group, max tow (3.73) anti spin diff, & slush mats.
Order:3/14, D:3/18, D1:3/21, E:?, F:4/14, 4/15 (Shipped), Dealer 4/25 and HOME now. 6-weeks exactly
Yella is offline   Quote Quick Reply
Old 03-02-2012, 11:28 PM   #3
Jeeper
 
rics1997's Avatar
 
Join Date: Oct 2010
Location: Bristol, Tn
Posts: 4,764
Well, you can get by with a 2012 and not regear but pre-2012 you really have to consider it. Especially a JKU. You might even get by with a 2 dr and 35's if you have a Rubi with 4.10 gears. But there really is a huge power drain with a JKU and 35's.

4.88 if 33's (and could still go to 5.13)
5.13 if 35's no question about it especially in a JKU

Have 4.88 and 33's and sometimes wish I went with 5.13 when towing. Freeway I am glad for 4.88.
__________________
2010 Dark Charcoal Pearl Jeep Wrangler Sport S Automatic
4.88 Yukon w/Trac-Lok rear and Eaton ELocker Front - Synergy Gussets - B&M 70264 Trans Cooler
BDS 3" lift - BDS Fox 2.0 Racing Shocks
XHD front Bumper - Trektop NX - Goodyear MT/R w/Kevlar 35X12.5X15 on MB Chaos 5 Wheels - Thrush Turbo Muffler

Become a WranglerForum Supporting Member!
rics1997 is offline   Quote Quick Reply
Old 03-02-2012, 11:38 PM   #4
Jeeper

WF Supporting Member
 
kbwwolf's Avatar
 
Join Date: Sep 2011
Location: Wisconsin
Posts: 12,128
Quote:
Originally Posted by JKERS View Post
I am ready to tackle the re-gearing of my rig, I am not sure whether to go with 4.88's or 5.13's in my '11 JKU, automatic trans, 35" tires......anyone with any experience or insight would be much appreciated.."..
I'm with Rick. The 4.88's would be a waste of $$ for your rig with 35's.

Take a look at the chart below. It's pretty general, but will give you a rough idea of where you'll be, rpm-wise, with various tires at speed on the highway. Don't go by mfr tire size, though. You want actual size. For example, my 35's are really 34", so that's what I'd use.

__________________


"What we see depends mainly on what we look for."
—John Lubbock
kbwwolf is offline   Quote Quick Reply
Old 03-02-2012, 11:56 PM   #5
Jeeper
 
Ricterslick's Avatar
 
Join Date: Jan 2012
Location: Denver
Posts: 55
Images: 3
I have a TJ running 35s and 5.13s. The pinon is small, but yay 5th gear. Glad I went so high.
Ricterslick is offline   Quote Quick Reply
Old 03-03-2012, 07:27 AM   #6
Jeeper
 
pkmcd99's Avatar
 
Join Date: Jan 2012
Posts: 2,117
After owning several Toyota trucks when I was younger, Ive come to the conclusion that most people on WF require to much power for how they drive. The toyota 22re is about one of the most tame four cylinder 4x4 power plants out there in its day. I had run 33-38.5 on various models and never regeared. Just compansated for power lost and drove according. The first generation JK with a 3.8l six banger is not a power beast, but even with the added weight, it still hauls better then my old yotas ever could. I dont believe running 34-35 tires is gonna suck the power any more then a yota on 38.5. Regearing certainly will put that arse dyno back where it should be, but I just cant justify 4k to switch both axles gear ratio out. Am I the only jeeper who thinks settling with stock gears is ok? I found on my yotas amd TJs for that matter, once you were in low range, you cant notice power robbing over sized tires, and out on the highway it isnt necessary to drive like you stole it. Dont gey me wrong, if I had the luxery to afford gears and labor I would be inclined to spend it, but in my world, stock is good enough for weekend warrior geo cache stuff.
pkmcd99 is offline   Quote Quick Reply
Old 03-03-2012, 08:32 AM   #7
Jeeper
 
JIMBOX's Avatar
 
Join Date: Nov 2009
Posts: 9,916
I've gotta '08 JKUR/auto/ 33.6" tires-

I would never go with a regear LESS than 5.13 gears/w auto--mine is 5.38 and for cruising/towing/off-road-I'd never get even 5.13s-

My JKUR weighs 5200 lbs avg and my power is great/mileage is good/throttle response-IMMEDIATE/O/D use even when towing is substancial !

It's expensive, so doit right !

JIMBO
__________________
"ya gotta have class"
JIMBOX is offline   Quote Quick Reply
Old 03-03-2012, 08:54 AM   #8
MTH
Jeeper
 
MTH's Avatar
 
Join Date: Oct 2010
Location: North Carolina
Posts: 8,553
For 35s with the 3.8 and an auto trans, my reading leads me to believe 5.36 would be the best choice.

Quote:
Originally Posted by pkmcd99
Regearing certainly will put that arse dyno back where it should be, but I just cant justify 4k to switch both axles gear ratio out.
$4k? Prices I've seen are generally south of $2k, no?
__________________
Mike
2010 JKU "Mountain" Edition
TeraFlex 2.5" Coil Lift : Old Man Emu Nitrocharger Shocks : 33x12.5R15 Goodyear DuraTracs : 15x8 Black Rock 909s : Other Stuff . . .
MTH is offline   Quote Quick Reply
Old 03-03-2012, 09:02 AM   #9
Jeeper
 
JIMBOX's Avatar
 
Join Date: Nov 2009
Posts: 9,916
YUP, generally $1200 to $2000 bucks, depends on the shop and GEARS/warranty/labor rate and rebuild kits-

Mine was YUKON/lubelockers/Master install kits/Synergy Ball joints/Valvoline fluid--$1958 bucks

Can'tbeatem

JIMBO
__________________
"ya gotta have class"
JIMBOX is offline   Quote Quick Reply
Old 03-03-2012, 09:03 AM   #10
Jeeper
 
pkmcd99's Avatar
 
Join Date: Jan 2012
Posts: 2,117
Quote:
Originally Posted by MTH
For 35s with the 3.8 and an auto trans, my reading leads me to believe 5.36 would be the best choice.

$4k? Prices I've seen are generally south of $2k, no?
Any shop ive looked into charges 10 hrs an axle plus parts and overnight lift fees. At 150 per hr, it adds up. Wish I had luxery of specialty shop that could do it cheaper and quicker
pkmcd99 is offline   Quote Quick Reply
Old 03-03-2012, 10:11 AM   #11
Jeeper

WF Supporting Member
 
denisbaldwin's Avatar
 
Join Date: Nov 2011
Location: Clearwater, FL
Posts: 3,293
I'm going with 4.88s myself so I can keep the Dana 30 up front.
__________________
Denis A. Baldwin
Clearwater, FL
1991 YJ 2.5L, 1" BD MML, 14 Bolt Rear, Dana 60 Front, 5.13 Gears, Detroit Lockers, 37ss, Cherokee Offset Springs (10" front to back stretch total), Bilstein 5150s, 1in. BL, custom cage, Warn M8000, Double D Dash/OHC, 4Low Front Stinger Bumper, DirtWorx Rear Bumper WTC, Tube Fenders, Comp Cut, 1 Ton HD Kingpin High Steering and PAID FOR.
denisbaldwin is offline   Quote Quick Reply
Old 03-03-2012, 11:35 AM   #12
MTH
Jeeper
 
MTH's Avatar
 
Join Date: Oct 2010
Location: North Carolina
Posts: 8,553
Quote:
Originally Posted by denisbaldwin
I'm going with 4.88s myself so I can keep the Dana 30 up front.
I thought they make 5.XXs for the D30 now?
__________________
Mike
2010 JKU "Mountain" Edition
TeraFlex 2.5" Coil Lift : Old Man Emu Nitrocharger Shocks : 33x12.5R15 Goodyear DuraTracs : 15x8 Black Rock 909s : Other Stuff . . .
MTH is offline   Quote Quick Reply
Old 03-03-2012, 11:37 AM   #13
Moderator

WF Supporting Member
::WF Moderator::
 
schnutzy's Avatar
 
Join Date: Sep 2009
Location: ring side seats to the the country's largest circus
Posts: 28,167
Send a message via AIM to schnutzy
Quote:
Originally Posted by MTH View Post
I thought they make 5.XXs for the D30 now?
those are for the D30s in the JK, which is different from the D30s used in the YJ and TJ
__________________
clinging on to sanity, one motorcycle at a time.
schnutzy is online now   Quote Quick Reply
Old 03-03-2012, 11:46 AM   #14
Because I Can

WF Supporting Member
 
TommyT's Avatar
 
Join Date: Jul 2011
Location: Buchanan Mi
Posts: 248
My 2011 is a 6 speed manual with 3:21 gears. If I am reading this chart right, when I go to 33's, 4:10 gears would be ideal for my DD light trail use jeep, Yes or no? Any reason to go bigger?
__________________
Proud USAF dad! 2011 Cosmos Blue Sport
"The best we can hope for concerning the people is that they be properly armed" ALEXANDER HAMILTON
TommyT is offline   Quote Quick Reply
Old 03-03-2012, 01:54 PM   #15
MTH
Jeeper
 
MTH's Avatar
 
Join Date: Oct 2010
Location: North Carolina
Posts: 8,553
Quote:
Originally Posted by schnutzy

those are for the D30s in the JK, which is different from the D30s used in the YJ and TJ
Yeah, I figured he was talking about JKs, since this is the JK section. But looking at his profile, I see I'm probably mistaken.

Quote:
Originally Posted by TommyT
My 2011 is a 6 speed manual with 3:21 gears. If I am reading this chart right, when I go to 33's, 4:10 gears would be ideal for my DD light trail use jeep, Yes or no? Any reason to go bigger?
I wouldn't worry about regearing of you've got a 6 speed, particularly if you stick with a lightweight set of 33s. My 3.21s handle my 33s no problem--all I changed is that I don't bother with 6th gear anymore.

If you were going to go through the expense of a regear, you'd want to shoot higher than 4.10s. They'd produce a "stock-ish" performance that'd hardly be worth the cost. For 33s, you'd go for 4.56s and for 35s you'd go for 4.88s, either of which would give you better than stock performance. And if you're paying close to $2k, I've got to think you want it better than stock.
__________________
Mike
2010 JKU "Mountain" Edition
TeraFlex 2.5" Coil Lift : Old Man Emu Nitrocharger Shocks : 33x12.5R15 Goodyear DuraTracs : 15x8 Black Rock 909s : Other Stuff . . .
MTH is offline   Quote Quick Reply
Old 03-03-2012, 05:28 PM   #16
Jeeper
 
zmotorsports's Avatar
 
Join Date: Mar 2012
Location: Northern Utah
Posts: 618
Quote:
Originally Posted by JKERS View Post
I am ready to tackle the re-gearing of my rig, I am not sure whether to go with 4.88's or 5.13's in my '11 JKU, automatic trans, 35" tires......anyone with any experience or insight would be much appreciated.."..
Is it the Rubicon model? Reason I am asking is front axle a d44 or d30?

If a d30 then I would go with the 5.13 gears. If a d44 (Rubicon) then I would go with the 5.38 gears.

In my opinion the 4.88 gears are what the automatic models should have come with from the factory. The 6-speed Rubicon models running 32" tires and 4.10 gears seem to be decent on the highway. They are running at near 2500 RPM. To get the automatic equiped JK to spin at that RPM they need a 4.88 gear with the 32" tires. Now jump up to 35" tires (actually measuring 33.75" in most cases) and you need to go to at least 5.13 preferabely 5.38 ratio.

My JKU runs right at about 2500 RPM @ 70 MPH on the interstate and the cruise hold fine with no hunting in/out of overdrive. My mileage went up after swapping out the 4.10 gears and around town it feels like a different Jeep. It actually can move out of its own way from a standstill vs. the 4.10 gears I thought I needed to push it to get it going.

Mike.
__________________
2011 JKU Rubicon
BDS Long-Arm System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Plus much, much more.

Click here to see my 2011 JKU Rubicon Build Thread
zmotorsports is offline   Quote Quick Reply
Old 03-03-2012, 05:34 PM   #17
Jeeper
 
zmotorsports's Avatar
 
Join Date: Mar 2012
Location: Northern Utah
Posts: 618
Quote:
Originally Posted by TommyT View Post
My 2011 is a 6 speed manual with 3:21 gears. If I am reading this chart right, when I go to 33's, 4:10 gears would be ideal for my DD light trail use jeep, Yes or no? Any reason to go bigger?
That is correct, 4.10 gear ratio would be great for the 33" tire. Before you have them re-geared ask yourself if there is a chance that you will ever go larger, say 35" or even 37". If so now is the time to gear properly as it is not cheap to re-gear multiple times. If you think you will ever go larger I would go with 4.88 gears otherwise I would suggest the 4.10 ratio that you are thinking about.

There are many that just don't use sixth gear and run in fifth. You can do that, however, you will not be taking advantage of the mechanical advantage of proper gearing for your Jeep. I am a huge fan of getting the mechanical leverage back into the vehicle after altering tire size.

Mike.
__________________
2011 JKU Rubicon
BDS Long-Arm System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Plus much, much more.

Click here to see my 2011 JKU Rubicon Build Thread
zmotorsports is offline   Quote Quick Reply
Old 03-03-2012, 06:13 PM   #18
Jeeper
 
Yella's Avatar
 
Join Date: Jul 2011
Location: St. Peters, Missouri
Posts: 735
With no regard to speed of the vehicle, what is the ideal rpm of the engine running down the highway mile after mile?
__________________

2008 JK Sport, lightly modded.
Ordered for Mrs Yella: 2014 Sahara JKU, Amp'd, auto, hard top, leather, 430 nav connect group, max tow (3.73) anti spin diff, & slush mats.
Order:3/14, D:3/18, D1:3/21, E:?, F:4/14, 4/15 (Shipped), Dealer 4/25 and HOME now. 6-weeks exactly
Yella is offline   Quote Quick Reply
Old 03-03-2012, 07:17 PM   #19
Jeeper
 
zmotorsports's Avatar
 
Join Date: Mar 2012
Location: Northern Utah
Posts: 618
Quote:
Originally Posted by Yella View Post
With no regard to speed of the vehicle, what is the ideal rpm of the engine running down the highway mile after mile?
Generally speaking one would say at the lowest possible RPM, however, that is not necessarily the case. At too low of an RPM the transmission will hunt in/out of overdrive on an automatic. Also with too low of an RPM, especially in a high profile vehicle with a large frontal area like our Jeeps, the engine may be at a low RPM but the throttle position/ injector PWM (Pulse Width Modulation) may be at a point where it is actually lugging the engine and working it too hard at a lower RPM, this also creates more heat that the cooling system must expel. This is more detrimental to an engine than a higher RPM and working the engine less.

In my opinion on the 3.8 liter engine that is in a Jeep JK which is usually lifted (changing the frontal area) which drastically effects the drag of the vehicle and also loaded up with extra weight from bumpers, winches, tires/wheels and everything else we load them up with I think the 2400-2700 RPM range is the sweet spot for cruising.

Mike.

__________________
2011 JKU Rubicon
BDS Long-Arm System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Plus much, much more.

Click here to see my 2011 JKU Rubicon Build Thread
zmotorsports 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
TRUE or FALSE caseyjoe Off-Topic 7219 04-16-2014 10:10 AM
89 or 93 octane? PedroJr TJ General Discussion Forum 62 12-04-2013 01:09 PM
Yes or No Game jgano23 Off-Topic 3637 05-16-2012 10:10 PM
what should i used hard or soft top? PedroJr North Carolina Jeep Forum 9 03-04-2012 03:18 AM
HID Kits... Yes or No? elundergan JK General Discussion Forum 10 03-02-2012 03:03 PM


logo carid shop wrangler parts carid fender flares custom wheels store avs deflectors at carid

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 11:08 AM.



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