Will I need to regear

WranglerMan

Well-Known Member
First Name
Will
Joined
May 8, 2018
Messages
2,820
Reaction score
1,977
Location
Katy Texas
Vehicle(s)
2018 Wrangler JLU Sahara
Occupation
Gas Pipeliner
Vehicle Showcase
1
A neighbor stopped by while I was washing my JLU Sahara after having my lift and new wheels/tires installed and liked the look a lot but then asked if I planned on regearing to which I replied why and he advised that going to bigger tires over stock requires it be done.

My stock setup was 275/70R18’s Bridgestone Duelers on stock Sahara wheels and my new setup is 315/70R17 KO2’s with Method MR312 -12 offset, it’s a auto tranny and does seem to hunt for the higher gear just aliitle but not bad





Advertisement

 

bilash31

Well-Known Member
Joined
May 17, 2017
Messages
399
Reaction score
377
Location
PA
Vehicle(s)
'14 JKU, '18 GC
Ok. Full disclosure. I don’t have a JL yet. But I am mostly up to speed on the forum. And I have an ‘18 GC with the 3.6/8 speed auto.

Do you HAVE to? Absolutely not. It will depend on the drive-ability to you. If you live in a flat state, you might not feel a need to get back some of the power. If you live in a really hilly or mountainous area, you may feel more power loss.

But many many people drove JKs for years with lower gearing and 315s. So I expect the JL will handle pretty easily. Search the forum. People have definitely posted their opinion on this matter already.

First thing you probably should do is have your computer flashed to the correct tire size to adjust your shift points. This can be done through aftermarket programmers or at the dealer.
 
OP
WranglerMan

WranglerMan

Well-Known Member
First Name
Will
Joined
May 8, 2018
Messages
2,820
Reaction score
1,977
Location
Katy Texas
Vehicle(s)
2018 Wrangler JLU Sahara
Occupation
Gas Pipeliner
Vehicle Showcase
1
  • Thread starter
  • Thread Starter
  • #3
Ok. Full disclosure. I don’t have a JL yet. But I am mostly up to speed on the forum. And I have an ‘18 GC with the 3.6/8 speed auto.

Do you HAVE to? Absolutely not. It will depend on the drive-ability to you. If you live in a flat state, you might not feel a need to get back some of the power. If you live in a really hilly or mountainous area, you may feel more power loss.

But many many people drove JKs for years with lower gearing and 315s. So I expect the JL will handle pretty easily. Search the forum. People have definitely posted their opinion on this matter already.

First thing you probably should do is have your computer flashed to the correct tire size to adjust your shift points. This can be done through aftermarket programmers or at the dealer.
Thanks for the reply, I have already ordered my Taser JL and setting the correct tire size and turning off ESS is going to be at the top of the list
 

millerjl

Well-Known Member
First Name
Chuck
Joined
Jun 28, 2018
Messages
460
Reaction score
336
Location
San Diego, CA
Vehicle(s)
JLU Rubicon
Vehicle Showcase
1
I was running 33's actually closer to 34 and a 2.5" lift on my JK with 3:10 gears and had no problems in socal. Sure you could feel it on some of the hills but was it worth the money to re-gear, not to me. The JL has 3:45 and the 8 speed transmission. You definitely don't need to...
 

WXman

Well-Known Member
Joined
Mar 1, 2017
Messages
2,513
Reaction score
2,316
Location
Central Kentucky
Vehicle(s)
2018 Wrangler Unlimited
Occupation
Meteorology and Transportation
The extra weight and diameter of the oversized tires is very noticeable, especially on JL because the vehicle is lighter than JK was. But, I find that after a few weeks your brain gets adjusted to it and it becomes the new normal. The Jeep drives fine, just requires a little more throttle.
 

Bingy

Well-Known Member
First Name
Dave
Joined
Mar 2, 2018
Messages
385
Reaction score
464
Location
Bailey, Colorado
Vehicle(s)
2018 Jeep Wrangler Sahara JLU
You don't need to on your Sahara. If you went with 37's then probably yes. I'm sure @TTEChris would advise you on maybe regearing on 37's, but not with your 315's...you are fine.
 

jerseymike

Well-Known Member
First Name
Mike
Joined
Feb 24, 2018
Messages
304
Reaction score
181
Location
Allentown, NJ
Vehicle(s)
2018 Wrangler JL Unlimited Sport S
I hear that with the auto you should be OK but I have a JLU sahara 6-speed manual and only 285/70/17 (plans to possibly go 315/70/17 in future) and I'm thinking of regearing to 4.10 or 4.56.

it is not a simple comparison to the JK as when I run the gear ratios, other than 1st gear the JL is geared the same in 2nd and much taller in 3-6th with the double overdrive such that a 3.73 in the JK is like 4.10 in the JL
 

butcho

Well-Known Member
Joined
Sep 2, 2018
Messages
227
Reaction score
211
Location
Charlotte, NC
Vehicle(s)
2018 Jeep Wrangler JLU
What’s optimal gearing for 35? 4.10 or one step higher?

(Sport S with factory 3.45)
 

vavaroutsos

Well-Known Member
First Name
Pete
Joined
Nov 24, 2017
Messages
620
Reaction score
396
Location
Scotts Valley, CA
Vehicle(s)
2015 Sprinter Crew Van 2500 High Roof 144" WB OM651 Brilliant Silver, 2019 JLR 3.6L 6SPD Granite Crystal
What’s optimal gearing for 35? 4.10 or one step higher?

(Sport S with factory 3.45)
With the manual transmission I would go 4.56 or even 4.88. I can't say for the automatic as I don't have experience with it. Some guys seem to be getting away with quite a large increase in tire size without re-gearing and they say they can still use 8th on the freeway. Other guys say it won't shift into 8th any more.
 

butcho

Well-Known Member
Joined
Sep 2, 2018
Messages
227
Reaction score
211
Location
Charlotte, NC
Vehicle(s)
2018 Jeep Wrangler JLU
With the manual transmission I would go 4.56 or even 4.88. I can't say for the automatic as I don't have experience with it. Some guys seem to be getting away with quite a large increase in tire size without re-gearing and they say they can still use 8th on the freeway. Other guys say it won't shift into 8th any more.
I have an automatic 8 speed and I can reach 8th gear but I want to potentially regear for MPG
 

JLCashBurn

Member
First Name
Kurt
Joined
Dec 2, 2018
Messages
7
Reaction score
6
Location
AZ
Vehicle(s)
2018 JL Unlimited
What’s optimal gearing for 35? 4.10 or one step higher?

(Sport S with factory 3.45)
4.56 is recommended by Jeep Engineers and Lift shops for 35's, 5.13 for 37s. I have fully tested your scenario out going from stock 3.45 to 4.56 on 35's. BIG difference in so many ways. (too much effort to write them all here). Mopar kit is available at this time.

Uninformed opinions in forums are not recommended.
 

rustyshakelford

Well-Known Member
Rock Sponsor (Level 1)
First Name
Brett
Joined
Sep 14, 2018
Messages
2,425
Reaction score
2,841
Location
Navasota, TX
Vehicle(s)
2019 JLUR-8 speed 2020 F-350
We’re still waiting for our Jeep to come in but when it does, there are Dana 5.13 and master install kits waiting to be installed in my shop. They should pair with the 6 speed and 37s great while only giving us 200-300 hundred rpm more at highway speed. 70 will now be 2200-2300 I believe. I would never regear to 4.10s. Not worth it, 4.56 at a minimum for 35s if you’re going to do it.

Jeep will have less than 5 miles before it gets its lift, skids and gears

Brett
 

Yoyo27983

Well-Known Member
Joined
Nov 21, 2018
Messages
55
Reaction score
11
Location
North Carolina
Vehicle(s)
2018 JLU billet
Not my experience at all. With a JLU sport, 3.43 auto. I installed the Mopar 2" and 33" 285/70R17 with Gearhead Big block rims.
8th is a thing of the past and gas mileage went from 25 to 15ish. Speedo is off -2 mph compared to gps app.
 

rustyshakelford

Well-Known Member
Rock Sponsor (Level 1)
First Name
Brett
Joined
Sep 14, 2018
Messages
2,425
Reaction score
2,841
Location
Navasota, TX
Vehicle(s)
2019 JLUR-8 speed 2020 F-350
Not my experience at all. With a JLU sport, 3.43 auto. I installed the Mopar 2" and 33" 285/70R17 with Gearhead Big block rims.
8th is a thing of the past and gas mileage went from 25 to 15ish. Speedo is off -2 mph compared to gps app.
Man I’ve seen you complain about the same thing in at least 3 different threads. That’s fine and all but please at a minimum be correct in what gears you’re complaining about. They are 3.45s

Brett
 

Advertisement




Hothead Headliners
 



Advertisement
Top