Sponsored

Tufelhundin

Well-Known Member
First Name
Windsor
Joined
Aug 17, 2019
Threads
1
Messages
319
Reaction score
341
Location
Louisiana
Vehicle(s)
2020 JT Sport S “sold”, 2022 JTR
Occupation
Gov
@Gren71

See that’s the kicker... I only saw 17mpg stock with 3.73’s.


My last tank was actually 17mpg. But that may be due to warmer temps/summer gas?

I have never seen some of the mpgs that are posted in this forum that’s for sure

It does pull my tandem trailer better... It will actually get into 7th at 65mph vice always staying in 5th. Seen 8th actually but it didn’t stay.
Sponsored

 

Gren71

Well-Known Member
First Name
Matt
Joined
Jul 9, 2019
Threads
143
Messages
3,999
Reaction score
6,331
Location
Delaware
Vehicle(s)
Jeep JT sports S Max Tow
Occupation
Magician
Vehicle Showcase
1
@Gren71

See that’s the kicker... I only saw 17mpg stock with 3.73’s.


My last tank was actually 17mpg. But that may be due to warmer temps/summer gas?

I have never seen some of the mpgs that are posted in this forum that’s for sure

It does pull my tandem trailer better... It will actually get into 7th at 65mph vice always staying in 5th. Seen 8th actually but it didn’t stay.
wow, well that going to 4.56 was probably a huge change for you. It would be nice to see 7th while pulling my trailer
 

Tufelhundin

Well-Known Member
First Name
Windsor
Joined
Aug 17, 2019
Threads
1
Messages
319
Reaction score
341
Location
Louisiana
Vehicle(s)
2020 JT Sport S “sold”, 2022 JTR
Occupation
Gov
@Gren71

Coming from 3.73 the 4.56 are awesome. I do feel confident if I had 4.10’s I would have stayed with them.

Best I could figure with the tires I have and the gearing I must be about 50rpm more at say 60-70 mph than a Max tow stock? Using the gearing calculator that’s been posted on here is what I used.
 

Gren71

Well-Known Member
First Name
Matt
Joined
Jul 9, 2019
Threads
143
Messages
3,999
Reaction score
6,331
Location
Delaware
Vehicle(s)
Jeep JT sports S Max Tow
Occupation
Magician
Vehicle Showcase
1
@Gren71

Coming from 3.73 the 4.56 are awesome. I do feel confident if I had 4.10’s I would have stayed with them.

Best I could figure with the tires I have and the gearing I must be about 50rpm more at say 60-70 mph than a Max tow stock? Using the gearing calculator that’s been posted on here is what I used.
yea, the 4.56s arent a huge difference in RPM coming from the 4.10s. Just a lot of chatter on here about how much nicer it is to pull a trailer with them vs the 4.10. My wife and I have a trip to Niagara booked next month. Thats going to be a 9 hour pull from Delaware so that will be the deciding factor for me.
 

syreeves

Well-Known Member
First Name
Steven
Joined
Nov 30, 2020
Threads
25
Messages
777
Reaction score
833
Location
Minnesota (aka Hoth)
Vehicle(s)
2021 JTR 6MT, 2013 Volvo XC90, 2003 LR Disco
Occupation
Liquor Attorney. So not all bad...
yea, the 4.56s arent a huge difference in RPM coming from the 4.10s. Just a lot of chatter on here about how much nicer it is to pull a trailer with them vs the 4.10. My wife and I have a trip to Niagara booked next month. Thats going to be a 9 hour pull from Delaware so that will be the deciding factor for me.
I'm interested to hear how it goes. 9hr pull may be a long haul... I have the Rubicon with the 6MT and gas v6. Stock 4.10 gearing. Mopar 2 inch lift (not sure that matters) with 35s. 38-40psi f/r. Last Saturday was 55F outside. Getting ready for camping season and pulled our 3500lb boy scout trailer (see pictures below) around for some errands. I could not maintain 65mph in 5th on cruise control heading east between Carver and Eden Prairie on 212E (just west of metro Minneapolis/St. Paul). Sometimes the speed dipped as low as 61 according to the digital speedo. [Yes - my speedo is adjusted for the tires] You can look it up on the interwebs - we're pretty flat out here with gentle grades... Anyway - as you can see the trailer is full and blunt and now I am not looking forward to pulling this thing to summer camp 4hrs away. This thread is telling me that I'm moving to 4.56s as soon as I can.

I took some pictures of the droop too - I estimate tongue weight around 600lbs and I dropped 2 inches at the rear wheel well. Only thing I had in the bed about 100lbs of crap (chainsaw, tool bag, and my stock rubi suspension that I am selling to a forum member.

Jeep Gladiator 35s & 4.56 gears experience 20210319_175207
Jeep Gladiator 35s & 4.56 gears experience 20210320_163057
Jeep Gladiator 35s & 4.56 gears experience 20210320_163109
Jeep Gladiator 35s & 4.56 gears experience 20210320_161123
Jeep Gladiator 35s & 4.56 gears experience 20210320_161629
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
 

Sponsored

Gren71

Well-Known Member
First Name
Matt
Joined
Jul 9, 2019
Threads
143
Messages
3,999
Reaction score
6,331
Location
Delaware
Vehicle(s)
Jeep JT sports S Max Tow
Occupation
Magician
Vehicle Showcase
1
I'm interested to hear how it goes. 9hr pull may be a long haul... I have the Rubicon with the 6MT and gas v6. Stock 4.10 gearing. Mopar 2 inch lift (not sure that matters) with 35s. 38-40psi f/r. Last Saturday was 55F outside. Getting ready for camping season and pulled our 3500lb boy scout trailer (see pictures below) around for some errands. I could not maintain 65mph in 5th on cruise control heading east between Carver and Eden Prairie on 212E (just west of metro Minneapolis/St. Paul). Sometimes the speed dipped as low as 61 according to the digital speedo. [Yes - my speedo is adjusted for the tires] You can look it up on the interwebs - we're pretty flat out here with gentle grades... Anyway - as you can see the trailer is full and blunt and now I am not looking forward to pulling this thing to summer camp 4hrs away. This thread is telling me that I'm moving to 4.56s as soon as I can.

I took some pictures of the droop too - I estimate tongue weight around 600lbs and I dropped 2 inches at the rear wheel well. Only thing I had in the bed about 100lbs of crap (chainsaw, tool bag, and my stock rubi suspension that I am selling to a forum member.

Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
the MPP lift will make a difference as the rear springs are..spongy-er, according to a handful of people on the forums. That may be where your sag comes from. You could try and WDH to try and level that out a bit. I also ordered these sumo spring inserst, they seem pretty cool.
https://www.etrailer.com/Vehicle-Suspension/SuperSprings/CSS-1195R.html

As far as the trailer pulling...yea Im kinda not looking forward to an entire trip in 4th and 5th. But like I said this trip will be the deciding factor. If its as annoying as Im assuming it will be 4.56s will be a no brainer. Even if I loose a little MPG in the end, the easier pulling would be worth it.
 

MrKnowitall

Well-Known Member
First Name
Guenther
Joined
Oct 4, 2018
Threads
0
Messages
468
Reaction score
343
Location
Detroit
Vehicle(s)
14 JKU-R
I'm interested to hear how it goes. 9hr pull may be a long haul... I have the Rubicon with the 6MT and gas v6. Stock 4.10 gearing. Mopar 2 inch lift (not sure that matters) with 35s. 38-40psi f/r. Last Saturday was 55F outside. Getting ready for camping season and pulled our 3500lb boy scout trailer (see pictures below) around for some errands. I could not maintain 65mph in 5th on cruise control heading east between Carver and Eden Prairie on 212E (just west of metro Minneapolis/St. Paul). Sometimes the speed dipped as low as 61 according to the digital speedo. [Yes - my speedo is adjusted for the tires] You can look it up on the interwebs - we're pretty flat out here with gentle grades... Anyway - as you can see the trailer is full and blunt and now I am not looking forward to pulling this thing to summer camp 4hrs away. This thread is telling me that I'm moving to 4.56s as soon as I can.

I took some pictures of the droop too - I estimate tongue weight around 600lbs and I dropped 2 inches at the rear wheel well. Only thing I had in the bed about 100lbs of crap (chainsaw, tool bag, and my stock rubi suspension that I am selling to a forum member.

Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
The Boyscout dad down the street traded from a half-ton to an Express 2500. No more cares about heavy brick shaped trailers.
 

syreeves

Well-Known Member
First Name
Steven
Joined
Nov 30, 2020
Threads
25
Messages
777
Reaction score
833
Location
Minnesota (aka Hoth)
Vehicle(s)
2021 JTR 6MT, 2013 Volvo XC90, 2003 LR Disco
Occupation
Liquor Attorney. So not all bad...
The Boyscout dad down the street traded from a half-ton to an Express 2500. No more cares about heavy brick shaped trailers.
Troop in the next town over owns an Express van (not sure if its 2500 or 3500) extended all the way so they can transport scouts rather than the parent convoy. He said a scout pukes in it every trip. We're sticking with the parent convoy and if a scout pukes in my JT then (a) I'm doing it right, and (b) they're hiking home... :CWL:
 

Wally's Dad

Active Member
First Name
Justin
Joined
May 21, 2021
Threads
6
Messages
33
Reaction score
19
Location
Shelby, NC
Vehicle(s)
2021 Gladiator
Occupation
Estimator, Preconstruction Manager
Several people asked me to post my experience with 4.56 gears, so here it is. I've got a 2021 Gladiator Overland, 3.6L V6 with manual transmission, which came with the 3.73 gears. A couple of months ago I added a Mopar 2" lift and 35 inch mud terrain tires. Last week, I had the gears swapped to 4.56. My goal for my build was to get a perfect blend between (1) a pretty darn nice daily driver truck (I came from a F150) and (2) a respectably offroad capable real Jeep. I think I have now achieved exactly that and I absolutely love the way it turned out:

Why I regeared: As soon as I added the lift and bigger tires, while still running the 3.73 gears, my truck felt severely under-powered. My gas mileage dropped from 17 mpg city/20 mpg highway to about 12 mpg no matter where I was driving. First gear starts became WAY more prone to stalling and felt very sluggish. On the highway, 5th and 6th gear became nearly useless--no power, no ability to maintain speed or pass in 5th or 6th, and constant downshifting. At 70 mph I was hitting about 2,000 rpm in 6th gear. If I hit even the slightest incline or wind, I could have the throttle completely opened up and would still be losing speed. I drive across Texas a lot, and through the Hill Country here in particular, so this was just intolerable for me.

Why I chose 4.56: I first thought about 4.10s. I talked to several "jeep people" online and in person, and everyone said regearing to 4.10 would be a waste of time and that I should be considering 4.56 or 4.88. So then I went back and forth between 4.56 and 4.88 a lot--reading forums about different experiences with each (mainly on the JL platform though--not as much info out there on the manual trans JTs), etc. I even changed my regear order back and forth a couple of times.

My main focus was increasing the RPMs in top gear back into the natural power band of the 3.6L V6 and restoring the fuel efficiency, but I also wanted a little more offroad performance vs my stock setup. The offroad shop that did the work estimated that with 4.56 gears in 6th gear at 75 mph, I would hit 2400-2500 RPM, and that would increase to 2600-2700 RPMs with 4.88s. The 4.88 option sounded like I would be running the engine a little harder than I wanted, but really would have been fine for the vehicle, and it would definitely have a lot of power. But first gear also would probably be really short with the 4.88s, and a lot of JL folks said their rides just felt a little too "tall" with the 4.88s and 35s.

Ultimately I went with the 4.56, which I determined would be just slightly over-geared compared to a stock Rubicon or Max Tow Sport (both have 4.10s) and would get the RPMs in a really good sweet spot on the highway... which sounded like exactly what I was going for.

After the regear: I just finished my 500-mile, grandma-driving break-in period on the new gears and had the gear oil drained and refilled. Now that I can drive normally again, my gas mileage has improved noticeably--roughly 17-18 mpg in the city and I've gotten similar results on short highway drives. Additionally, throughout 1st-6th gear there is significantly more power. My truck is noticeably peppier than stock off the line, and starts are much easier... let out the clutch and the truck does most of the work. 1st is quick and full of torque, but not so much that it feels like I'm driving a tractor... feels more like the power you'd get in a V8 full-size truck off the line. 5th and 6th gear maintain speed on the highway with absolutely no problem, even in hills and wind.. with no downshifting needed so far. I can accelerate to pass in 6th (which I could barely do even before the lift & tires). I'm at exactly 2,500 rpms at 75mph which feels perfect on this engine. It will be so nice to have functional cruise control in this thing now!

I'm taking it to Moab pretty soon and will report back on the long-drive and offroad experience, but so far the 4.56 seems to be the absolute sweet spot.... a little sportier feeling than a stock rubicon, but not so much that it feels like a weekend-only vehicle. Fuel efficiency is respectable so far, and it's very responsive and powerful through all gears. Feels to me like 4.88s would have been a little too much for what I was going for, and so far couldn't be happier with the pairing of 4.56s on 35 inch tires.

IMG_4286.JPG
IMG_4314.JPG
Man...this is EXACTLY the write-up I have been looking for!! THANK YOU!!! 4.56 it is!! I was soo close to making the mistake of going 4.10s.
 
Last edited:

DanW

Well-Known Member
First Name
Dan
Joined
Mar 2, 2017
Threads
23
Messages
939
Reaction score
1,104
Location
Brownsburg, Indiana
Vehicle(s)
21 JT Rubi, 18 JLU Rubi, 2008 JKU Rubi, 07 Vette
Man...this is EXACTLY the write-up I have been looking for!! THANK YOU!!! 4.56 it is!! I was soo close to making the mistake of going 4.10s.
That's the way I'm going. I've got my Dana/Spicer 4.56 rings/pinions and the front Master Overhaul kit. I'm just waiting on the rear kit and then a good friend that runs a Jeep mod shop will install them. I'm really looking forward to what this does to 5th and 6th gear! The Jeep is great and is quick, to in 1-4 (I have 4.10's and 35's) but man, 5th and 6th leave much to be desired. I suspect it'll give 1-4 a kick in the pants, too!
 

Sponsored

starttodaynola

Well-Known Member
First Name
Drew
Joined
Jun 15, 2019
Threads
3
Messages
46
Reaction score
2
Location
New Orleans
Vehicle(s)
2020 Gladiator Overland
If I wasn’t towing a travel trailer, I would not have regeared. 4:10 was plenty for 35s. I think I would have only considered regearing with 37s.

my 35s are only 3lbs heavier than stock ones, and I’m running stock rims. I could not feel that weight gain difference. The thing I could feel was the steering. It felt a little heavier because added grip. You get used to that in the first day and don’t notice it anymore.

shameless photo of my Gladiator on 35s...



Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
What tires are those?
 

starttodaynola

Well-Known Member
First Name
Drew
Joined
Jun 15, 2019
Threads
3
Messages
46
Reaction score
2
Location
New Orleans
Vehicle(s)
2020 Gladiator Overland
I'm interested to hear how it goes. 9hr pull may be a long haul... I have the Rubicon with the 6MT and gas v6. Stock 4.10 gearing. Mopar 2 inch lift (not sure that matters) with 35s. 38-40psi f/r. Last Saturday was 55F outside. Getting ready for camping season and pulled our 3500lb boy scout trailer (see pictures below) around for some errands. I could not maintain 65mph in 5th on cruise control heading east between Carver and Eden Prairie on 212E (just west of metro Minneapolis/St. Paul). Sometimes the speed dipped as low as 61 according to the digital speedo. [Yes - my speedo is adjusted for the tires] You can look it up on the interwebs - we're pretty flat out here with gentle grades... Anyway - as you can see the trailer is full and blunt and now I am not looking forward to pulling this thing to summer camp 4hrs away. This thread is telling me that I'm moving to 4.56s as soon as I can.

I took some pictures of the droop too - I estimate tongue weight around 600lbs and I dropped 2 inches at the rear wheel well. Only thing I had in the bed about 100lbs of crap (chainsaw, tool bag, and my stock rubi suspension that I am selling to a forum member.

Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
Jeep Gladiator 35s & 4.56 gears experience 20210320_161745
What wheels are those?
 

PDiddy

Well-Known Member
First Name
Paul
Joined
Aug 17, 2020
Threads
14
Messages
811
Reaction score
1,964
Location
Roseville
Vehicle(s)
2020 Jeep Gladiator Rubicon
Occupation
Architectural Illustrator
What tires are those?
They Are Cooper Evolution M/Ts. 35s on stock 17s. I want with them because they are very light weight for a M/T and look good.
 

Hipbilly

Well-Known Member
First Name
Jimmy
Joined
Dec 4, 2019
Threads
9
Messages
286
Reaction score
467
Location
North Little Rock, AR
Vehicle(s)
2020 Gladiator Sport, 2007 FJ Cruiser
A good confirmation for my current plan. I’m in the exact same “before” boat, with the same headaches, did the math and arrived at the same decision for the same reason…. I’m glad I’m right and haven’t even done it yet!
Sponsored

 
 



Top