WELCOME TO RIVER DAVES PLACE

Jeep JKU with 3:73 gears, pig or not.

2Driver

Well-Known Member
Joined
Dec 21, 2007
Messages
14,977
Reaction score
24,076
I’ve been looking for a low mile JKU and found one that meets most my needs except it has 3:73 vs 4:10 I’ve always had 4:10 s.

If I just run a 2” lift and 34 11:50s will it be a pig or negligible?
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
I think at some point youll want to go to the 410's. This setup is really similar to mine i will say its a pig and im looking to regear at some point. But it does fine off roading and on the highway for now.
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
IMG_20230101_162818972_HDR.jpg
IMG_20230101_162747045_HDR.jpg
KIMG0599.JPG
 

Gelcoater

Well-Known Member
Joined
Sep 26, 2009
Messages
20,265
Reaction score
30,782
I’ve been looking for a low mile JKU and found one that meets most my needs except it has 3:73 vs 4:10 I’ve always had 4:10 s.

If I just run a 2” lift and 34 11:50s will it be a pig or negligible?
Is it more an on or off road rig?
If more on road I’d run the hearing in it.
If more off, I’d go 4:10 or even 4:30
 

pwerwagn

Inmate #4800
Joined
Aug 28, 2010
Messages
2,335
Reaction score
2,583
I’ve been looking for a low mile JKU and found one that meets most my needs except it has 3:73 vs 4:10 I’ve always had 4:10 s.

If I just run a 2” lift and 34 11:50s will it be a pig or negligible?

What year JKU? The 3.8 vs the 3.6 makes a big difference.
 

2Driver

Well-Known Member
Joined
Dec 21, 2007
Messages
14,977
Reaction score
24,076
On and off road 3.6 2017 JKU. I’d only need 34’s. How much to regear to 4:10’s $2k?

Damn, every time I find the right jeep it’s close except for 1 item.
 
Last edited:

bldrinker

Well-Known Member
Joined
Sep 28, 2011
Messages
6,696
Reaction score
12,225
My 2015 on 35’s with 4:10’s didn’t have a problem if you are ok with 4,000rpm climbing hills and getting 12mpg on the highway
 

bldrinker

Well-Known Member
Joined
Sep 28, 2011
Messages
6,696
Reaction score
12,225
On and off road 3.6 2017 JKU. I’d only need 34’s. How much to regear to 4:10’s $2k?

Damn, every time I find the right jeep it’s close except for 1 item.
If it’s a second vehicle you will get by with the 4:10. Daily you will want to gear it.
 

bldrinker

Well-Known Member
Joined
Sep 28, 2011
Messages
6,696
Reaction score
12,225
Is it more an on or off road rig?
If more on road I’d run the hearing in it.
If more off, I’d go 4:10 or even 4:30
You have that backwards.

Off road it’s fine especially if it’s a Rubicon that 4:1 transfer case is all the gearing you need.

On the highway it don’t have the brand to maintain 75-80 without flogging it pretty good
 

Bigbore500r

Well-Known Member
Joined
Apr 28, 2014
Messages
15,946
Reaction score
30,360
I’ve been looking for a low mile JKU and found one that meets most my needs except it has 3:73 vs 4:10 I’ve always had 4:10 s.

If I just run a 2” lift and 34 11:50s will it be a pig or negligible?

We have a 2012 JKU on 35's. First year of the 3.6 Pentastar. It does fine with 3.73. Gets 13 city, 15 highway for the last 5 years we've had it. Could use more gear but honestly it works well enough that I don't bother. Running 35x12/5x20 Nitto Trail Grapplers, Mopar 4" lift. It has 125k miles on it now.....been running 35's it's whole life
 

SPYLIFE

Well-Known Member
Joined
Apr 13, 2018
Messages
135
Reaction score
121
2012 JKU I've had since new with 37's it's entire life. I did not do the gear change, and it's an automatic w/3.73's. I had it first in FL for several years and had no problems with the flat area at all. I took it out to Maricopa County for several years and had no problems either. It's never been a daily driver, and what many call a "mall crawler". It was a little slow going up The 17 to Flagstaff, but we still made it fine. I even towed a couple MX bikes with it a few times in a 10' box trailer. I'm sure it could be better, but for no off-roading, and cruising around town on a nice day, I've never had a single issue with stock gears. It has about 60K miles on it now.
 

DRYHEAT

Well-Known Member
Joined
Sep 6, 2010
Messages
6,068
Reaction score
10,547
I’ve been looking for a low mile JKU and found one that meets most my needs except it has 3:73 vs 4:10 I’ve always had 4:10 s.

If I just run a 2” lift and 34 11:50s will it be a pig or negligible?
Not sure what your ultimate goal is but I wouldn’t do it unless you’re going to go 4.56 or 4.88. I think you’d be disappointed with the step from 3.73’s to 4.10s.
 

2Driver

Well-Known Member
Joined
Dec 21, 2007
Messages
14,977
Reaction score
24,076
Continue looking, but for a Rubicon JKU. It will have Dana 44s at both ends, lockers in both axles, 4.10 gears and a 4 to 1 transfer case. You will be much happier if you do any off roading.

Its a Rubicon Recon of all models All Rubicons come stock with 3:73’s 4:10 is actually an option. I think the 3:73 is more standard in flat states. TX and back east
 

Ol Man

Well-Known Member
Joined
Dec 20, 2007
Messages
746
Reaction score
676
Its a Rubicon Recon of all models All Rubicons come stock with 3:73’s 4:10 is actually an option. I think the 3:73 is more standard in flat states. TX and back east
I know my 2008 came with 4.10s. I now run 37s with 5.13.
 

mesquito_creek

Well-Known Member
Joined
Sep 25, 2009
Messages
2,939
Reaction score
3,894
Its a Rubicon Recon of all models All Rubicons come stock with 3:73’s 4:10 is actually an option. I think the 3:73 is more standard in flat states. TX and back east

My 2016 JKU rubicon came with 4:10 as an option, just as you stated. It needs every bit of the gear with 35s. Works well but needs that extra gear. Gas mileage blows at 14mpg.
 

sintax

Well-Known Member
Joined
Mar 7, 2008
Messages
5,695
Reaction score
8,729
something worth mentioning....

If we're talking Dana 44 axles, the differential carrier split is 3.73 and down, and 3.92 and up.

So if you're at 3.73's already, and you want to go up into the 4's youre going to need new lockers (assuming we're talking a Rubi) or at a bare minimum new carriers. Thats where shit gets expensive. Setting up a set of gears is really not much work, but the parts aint cheap.

When I first started getting into wheeling, you could pick up an ARB for a D44 for $650, now they run $1250
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
So whats an all in cost to regear at a reputable shop?
Summit 4x4 up here in prescott. Which is pretty darn reputable for jeeps and toyotas costs $5k front and rear cant remember what type of locker i imagine air or electric.

But i think thats just have the locker im the axle not hooking it up. I cant remember but its in that ball park either way.
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
Close to it theyre freaking metric! Its the wifes daily and by that i mean she also fills up daily. Jk a tank of gas on the road doesn't go far at all. But as for wheeling weve done some pretty incredible trails just fine but i still would like to add on the options that the Rubicon's come with.

Also its the 3.8L

But when that sucker goes a v8 is going in already been blessed by the wife
 

hman442

Well-Known Member
Joined
Mar 7, 2021
Messages
651
Reaction score
1,384
The early Rubicons did come with 4.10s. Apparently, more recently, they started doing 3.73s with optional 4.10s. Maybe to help hit the Feds. fuel economy numbers ?
 

2Driver

Well-Known Member
Joined
Dec 21, 2007
Messages
14,977
Reaction score
24,076
Lots of great info. Kicking myself for selling my 2017 rubi recon. Im going to shop and wait for the right jeep

There was a killer recon in Havasu craigslist 3 weeks ago and I missed it.

I'll find something then the Gladiator goes bye bye
 

mjc

Retired Neighbor
Joined
Jan 3, 2008
Messages
10,727
Reaction score
7,159
Lots of great info. Kicking myself for selling my 2017 rubi recon. Im going to shop and wait for the right jeep

There was a killer recon in Havasu craigslist 3 weeks ago and I missed it.

I'll find something then the Gladiator goes bye bye
I might be interested the Gladiator when the time comes.
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
While were on the topic of gearing and axles and such. I know we have the loyalists here but

What locker are you running and why?

Im on the fence about air/electric, has anyone given OX lockers a chance?
 

poncho

Well-Known Member
Joined
Dec 20, 2007
Messages
4,051
Reaction score
4,768
Pig.
That V6 needs all the help it can get.
Sold my Wifes 2018 Sahara last year, couldn't believe what a dog that was, came home from a trip and told her my Kia midsize rental felt like a race car compared to her Jeep, i understand the weight and running gear differences but her jeep was a slug.
 

pronstar

President, Dallas Chapter
Joined
Aug 5, 2009
Messages
32,977
Reaction score
36,954
Not sure what your ultimate goal is but I wouldn’t do it unless you’re going to go 4.56 or 4.88. I think you’d be disappointed with the step from 3.73’s to 4.10s.
100%
I usually like to take two steps minimum when I change gears.
While were on the topic of gearing and axles and such. I know we have the loyalists here but

What locker are you running and why?

Im on the fence about air/electric, has anyone given OX lockers a chance?

I’m in the same boat…plus considering another Torsen LSD, I had good experience with it on my Ram.

The G80 GM uses in trucks is hot garbage.
 

sintax

Well-Known Member
Joined
Mar 7, 2008
Messages
5,695
Reaction score
8,729
While were on the topic of gearing and axles and such. I know we have the loyalists here but

What locker are you running and why?

Im on the fence about air/electric, has anyone given OX lockers a chance?


This topic is way more of a debate than a discussion, theres no clear winner in any situation.

I'd say you have to look at things this way...

1) you gotta determine your goals. Is this a dedicated offroad rig?? Daily driver that sees offroad once or twice a year??
2) how much additional infra / wiring are you cool with setting up?
3) how much are you willing to pay?


Real high level here...

lunch box lockers - cheapest, easiest to install, no infra needed, weakest setup, outside of a spool worst handling on the road, unpredictable on ice (esp front)
Detroit style mechanical - no infra, super strong, not the most friendly onroad esp if you have a heavy right foot
ARB - expensive, needs air infra (go full pneumatic if you can, avoid the solenoids), weak air line (but you can convert), great on/offroad, weak seals
OX - expensive, great on / off road, exposed cable mechanism prone to rock damage, seen the cable getting damaged and stuck.
mechanical lsd - not cheap really, great onroad, so-so offroad, prob a decent choice for the guy who wont see much offroad
clutch lsd - skip
 

DLC

Well-Known Member
Joined
Jan 18, 2013
Messages
8,004
Reaction score
10,641
Lots of good info in here!

2012 JKU on 37’s w/ 513’s automatic trans - rubi
2005 LJ on 35’s w/ 488’s and 6 speed manual - rubi

I had a 98 TJ 33’s w/ 456’s it was great ! drove nice on the highway and off-roading

the 2012 works great but sucks for longer drives, if you drive on pavement A lot get the 488’s it’s a bit more “ on road “ friendly

I would NOT pay to go from 373 to 410 to close to each other
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
Sold my Wifes 2018 Sahara last year, couldn't believe what a dog that was, came home from a trip and told her my Kia midsize rental felt like a race car compared to her Jeep, i understand the weight and running gear differences but her jeep was a slug.
Haha wife and kiddos think my Subaru Forester daily driver is a race car compared to our jeep to 😂
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
This topic is way more of a debate than a discussion, theres no clear winner in any situation.

I'd say you have to look at things this way...

1) you gotta determine your goals. Is this a dedicated offroad rig?? Daily driver that sees offroad once or twice a year??
2) how much additional infra / wiring are you cool with setting up?
3) how much are you willing to pay?


Real high level here...

lunch box lockers - cheapest, easiest to install, no infra needed, weakest setup, outside of a spool worst handling on the road, unpredictable on ice (esp front)
Detroit style mechanical - no infra, super strong, not the most friendly onroad esp if you have a heavy right foot
ARB - expensive, needs air infra (go full pneumatic if you can, avoid the solenoids), weak air line (but you can convert), great on/offroad, weak seals
OX - expensive, great on / off road, exposed cable mechanism prone to rock damage, seen the cable getting damaged and stuck.
mechanical lsd - not cheap really, great onroad, so-so offroad, prob a decent choice for the guy who wont see much offroad
clutch lsd - skip
Thanks for the breakdown. What are your thoughts if any about Eaton e-lockers.
 

sintax

Well-Known Member
Joined
Mar 7, 2008
Messages
5,695
Reaction score
8,729
Thanks for the breakdown. What are your thoughts if any about Eaton e-lockers.

I think they're a really good option, same price roughly as ARB's. Performance wise I'd say the couple people I know that have them have been happy. Thats really the biggest issue as I see it, the market share is not quite up to ARB.

Supposedly ARB has really worked out a lot of bugs lately, and some of the big name dudes who run them have shown they can handle the abuse. I've seen dudes engage / disengage their ARB's while on the rev-limiter.

I think you just have to debate if you have any interest in running onboard air, either an air compress or CO2. If you're feeling you want that anyways, it might just make sense to go the ARB route. I run a 10lb CO2 tank in my XJ, I have it plumbed into the air system and just use that. The way I set it up theres no electronic parts in the mix, just trying to limit the amount of things to break / go wrong.
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
I think they're a really good option, same price roughly as ARB's. Performance wise I'd say the couple people I know that have them have been happy. Thats really the biggest issue as I see it, the market share is not quite up to ARB.

Supposedly ARB has really worked out a lot of bugs lately, and some of the big name dudes who run them have shown they can handle the abuse. I've seen dudes engage / disengage their ARB's while on the rev-limiter.

I think you just have to debate if you have any interest in running onboard air, either an air compress or CO2. If you're feeling you want that anyways, it might just make sense to go the ARB route. I run a 10lb CO2 tank in my XJ, I have it plumbed into the air system and just use that. The way I set it up theres no electronic parts in the mix, just trying to limit the amount of things to break / go wrong.
Thats a cool idea. Never really thought about running it off a tank. Im of the same mindset less moving parts equals less things to break.
 

sintax

Well-Known Member
Joined
Mar 7, 2008
Messages
5,695
Reaction score
8,729
Thats a cool idea. Never really thought about running it off a tank. Im of the same mindset less moving parts equals less things to break.

So to break it down...

I have a 10lb tank in the back, the tank has a co2 regulator on it, for lockers you want it adjust to about 90 lbs. That is fed into a manifold via the normal air hose chuck. This manifold is pretty simple, just an IN, a pressure relief, and an OUT. The out is 1/4" nylon Air Brake line that runs along the floorboards forward. Here you could T it off into something else, but I just have it running straight into Clippard MJTV-3 pneumatic switch. It has 3 ports on the switch (IN,OUT,VENT), air goes in, and if the switch is on, it routes it to the ARB. When its turned off, it bleeds the line pressure off to the cab, and stops the flow of CO2. I run the OUT via a stainless vinyl coated brake soft line to the ARB bulkhead in the axle pumpkin. One of the biggest issues w/ the ARB is the electrical wiring / solenoids, and the crummy cheap plastic air lines that always break.

My solution fixes both of those issues.


CF136139-9CCD-421B-BF08-788CD153E398.jpeg


AD291F02-2101-4A47-8903-A52DF07E5315.jpeg


7345EF1A-7674-4EB6-8554-0327082FEEB4.jpeg
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
So to break it down...

I have a 10lb tank in the back, the tank has a co2 regulator on it, for lockers you want it adjust to about 90 lbs. That is fed into a manifold via the normal air hose chuck. This manifold is pretty simple, just an IN, a pressure relief, and an OUT. The out is 1/4" nylon Air Brake line that runs along the floorboards forward. Here you could T it off into something else, but I just have it running straight into Clippard MJTV-3 pneumatic switch. It has 3 ports on the switch (IN,OUT,VENT), air goes in, and if the switch is on, it routes it to the ARB. When its turned off, it bleeds the line pressure off to the cab, and stops the flow of CO2. I run the OUT via a stainless vinyl coated brake soft line to the ARB bulkhead in the axle pumpkin. One of the biggest issues w/ the ARB is the electrical wiring / solenoids, and the crummy cheap plastic air lines that always break.

My solution fixes both of those issues.


View attachment 1192764

View attachment 1192765

View attachment 1192766
Thats a clean setup! I actually have access to a free Co2 tank. I would just need to recertify the tank and do a regulator setup i was looking at the power tank regulator and also searched the diy reg setup.

Haha thanks for getting me wheel's spinning and making me think about another project for my Jeep.
 

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
1,857
Reaction score
3,073
Has anyone here done their own gear change? I have researched this and i have access to the tools and a a knowledgeable mechanic to double check if something doesn't seem correct.

Doesn't seem overly complicated if you have the patience and time to do it and not be rushed. Am i thinking completely wrong?
 

LargeOrangeFont

We aren't happy until you aren't happy
Joined
Sep 4, 2015
Messages
42,336
Reaction score
61,233
Has anyone here done their own gear change? I have researched this and i have access to the tools and a a knowledgeable mechanic to double check if something doesn't seem correct.

Doesn't seem overly complicated if you have the patience and time to do it and not be rushed. Am i thinking completely wrong?

Not hard, just a little tedious.
 

81Sprint

Well-Known Member
Joined
Jul 26, 2010
Messages
1,117
Reaction score
2,883
Has anyone here done their own gear change? I have researched this and i have access to the tools and a a knowledgeable mechanic to double check if something doesn't seem correct.

Doesn't seem overly complicated if you have the patience and time to do it and not be rushed. Am i thinking completely wrong?
I've done it, I won't do it again. One of those things to leave to someone who does it on the daily and knows the tricks IMO
 
Top