Jeep 392 and 3.73 rear end

Jr87mustang

Black Diamond
Well-Known Member
First Name
Josh
Joined
Aug 24, 2020
Messages
1,803
Reaction score
5,042
Location
Northern Cali
Vehicle(s)
2019 Ford Expedition, 1987 5.0 GT Convert
Bronco
Black Diamond
My uncle ordered the Jeep 392 and I was just poking around on the Jeep website checking it out. Is it odd that it only comes with a 3.73 rear end and not even the 4.10 that comes with the standard Rubicon? I understand it has more torque so maybe its a limiting device to keep from breaking parts? Anyone have any ideas on that? Also thought it was funny that it didn't come with 35's.
Advertisement

 

Rivers90

Base
Well-Known Member
First Name
Ben
Joined
Jul 4, 2020
Messages
694
Reaction score
1,061
Location
california
Vehicle(s)
xterra mx5
Bronco
Base
Often vehicles with more power come with a higher gear ratio. So not a surprise. Also you need to look at the transmission gearing too for a full comparison.
The 392 has so much power the tires will spin with any gearing.
Jeep just does not offer 35's from the factory on the wrangler.
 

Bronco4lyfe85

Badlands
Well-Known Member
First Name
William
Joined
Aug 17, 2020
Messages
5,052
Reaction score
17,865
Location
Colorado
Vehicle(s)
2019 Challenger Scat Pack
Bronco
Badlands
Often vehicles with more power come with a higher gear ratio. So not a surprise. Also you need to look at the transmission gearing too for a full comparison.
The 392 has so much power the tires will spin with any gearing.
Jeep just does not offer 35's from the factory on the wrangler.
Yep, my scat pack comes with 3.09 gears. The 392 will smoke tires from a stand still with very light throttle pressure. I can’t even count on 2 hands the times I’ve accidentally barked the tires from a stop light just trying to hit the gas.
 

Spooled

Badlands
Well-Known Member
Joined
Mar 3, 2020
Messages
1,290
Reaction score
4,982
Location
Republic of Texas
Vehicle(s)
2017 F-150, 2021 ZR2
Bronco
Badlands
Clubs
 
The 2nd generation 8HP75 has some pretty aggressive ratios. That combined with the tire size, 3.73 axle ratios, and 6.4 torque means anything lower geared would be overkill for a it.

Compared to a Badlands (same size tires), it will cruise the highway at a lower rpm though by about 300rpm.
 

MSparks909

Badlands
Well-Known Member
First Name
Miles
Joined
Jul 22, 2020
Messages
232
Reaction score
612
Location
ENC
Vehicle(s)
2014 Ford F-250
Bronco
Badlands
Easy fix.
392XR with 4.56
Yep. I’ll be jumping to 37” KM3s once I get my 392XR broken in. GF is switching her order to a Black Diamond 4dr. Sasquatch so I’ll still have a good idea of how they compare wheeling wise. She plans to take her Bronco to Uwharrie when I take my Jeep and wants to make an eventual trip out to Moab. We rented a JL Rubicon on 37s in Moab last week and she now sees the benefits of lockers, etc 😎
 

Bison

Badlands
Well-Known Member
First Name
Matt
Joined
Jul 24, 2020
Messages
467
Reaction score
1,057
Location
Colorado
Vehicle(s)
Fj cruiser, Power wagon
Bronco
Badlands
We have the diesel with 3.73’s. The thing is perfect. If we ever do 37’s we will probably end up with 4:56’s.
 

ekim

Badlands
Well-Known Member
First Name
Mike
Joined
Aug 16, 2020
Messages
147
Reaction score
398
Location
NJ
Vehicle(s)
Jeep TJ, Ford Excursion
Bronco
Badlands
It used to be the case that 37s required 35 spline axle shafts and at least a 9" ring and pinion in the rear and maybe a 8.8 in the front.

Have the new OEM axles really come that far?
 

Classic Lover

Member
Joined
Aug 16, 2021
Messages
23
Reaction score
66
Location
IL
Vehicle(s)
2021 Dodge Challenger T/A 392
Bronco
Undecided
Often vehicles with more power come with a higher gear ratio. So not a surprise. Also you need to look at the transmission gearing too for a full comparison.
The 392 has so much power the tires will spin with any gearing.
Jeep just does not offer 35's from the factory on the wrangler.
You can get the wrangler with 35s now if you order the xtreme package.
 

Bronco21fan

Black Diamond
Well-Known Member
First Name
Angelo
Joined
Jul 11, 2020
Messages
1,835
Reaction score
3,512
Location
NewJersey
Vehicle(s)
2013 vw gti
Bronco
Black Diamond
My uncle ordered the Jeep 392 and I was just poking around on the Jeep website checking it out. Is it odd that it only comes with a 3.73 rear end and not even the 4.10 that comes with the standard Rubicon? I understand it has more torque so maybe its a limiting device to keep from breaking parts? Anyone have any ideas on that? Also thought it was funny that it didn't come with 35's.
You can add the recon pakage to it that gives it 35s
 
OP
OP
Jr87mustang

Jr87mustang

Black Diamond
Well-Known Member
First Name
Josh
Joined
Aug 24, 2020
Messages
1,803
Reaction score
5,042
Location
Northern Cali
Vehicle(s)
2019 Ford Expedition, 1987 5.0 GT Convert
Bronco
Black Diamond
You can add the recon package to it that gives it 35s
Yes, it does now. He ordered it in January-ish and they didn't have 35s. The XR had not even been whispered yet. He is PISSED now. If he had ordered about 2 months later he could have gotten the XR package. O well 🤷‍♂️
 

BigHoof

Badlands
Well-Known Member
Joined
Feb 7, 2021
Messages
211
Reaction score
480
Location
Western PA
Vehicle(s)
Ram 2500
Bronco
Badlands
Yes, it does now. He ordered it in January-ish and they didn't have 35s. The XR had not even been whispered yet. He is PISSED now. If he had ordered about 2 months later he could have gotten the XR package. O well 🤷‍♂️
Also gets you 4:56 gears and some other goodies.
 
Advertisement

 
Zone Offroad
Advertisement
Top