392 Recon 4.56 Rear End?

Brokenboat

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First things, first. Love my 392. Lets get that out of the way. So happy with my decision. Bronco/Range Rover who???

I have a 2021 392 with 3.73 rear end. Took delivery in June of 2021. As soon as I took delivery, I swapped out the BFG KO2 33's for BFG KO2 35's. I am very happy with the ride quality noting that the 35's seem to provide a bit more of a "squishy" feel than the 33's, but not by much. I did not recalibrate yet and just note the speed and RPM differences while driving.

I guess I have a couple of questions?

  • Has anyone experienced any issues swapping out to the 35's? If so, what are your experiences?
  • The rear end is the 3.73 and with the new Recon, they have upgraded to the 35's but changed to 4.56 rear end. What does this change bring to the mix? Why is the 4.56 preferrable? Or... is it?

Clearly, the new Recon has some cool stuff that we all wish was on our original 2021's, but to me, all mods are now up to us rather than Mopar, which is more fun anyway. One thing I just did order was the Mopar fender flare extensions. They look pretty cool and will cover the extra width (not that this is a legal requirement here in NH). They are backordered forever, probably, but I'm a patient sort.

I have a few more mods in the works (winch, primarily) and once I hit 10K, I'm going to pull together all of my thoughts and post them for review. Right now, there are a few things eating at me...

  • The drip rails on the side roof lines seem to drip right into the front door when open. Ill conceived design.
  • Fuel tank needs to be a few gallons bigger (5 more would be great). Range is limited, even at 14.7 MPG. She never misses a gas station, that is for sure.
  • Steering, as many have mentioned, is not tight or precise - or even close. Would love to figure that one out.

Thanks for any thoughts. Wishing all my fellow 392 riders a Happy New Year.

Dan
 

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I went with 17x9 wheels with Nitto 35X12.5 and adjusted tire size with the Tazer. So far I do not feel any need for a gear change and really didn't notice a difference. Steering felt good before and after. I did install a Teraflex 1" spacer to level it out after the winch and lights.
 
I also have a regular 392, and I also swapped to 35” tires. I did make the computer change with a Tazer, and that helped with the gear changes, etc.

I already have my 4.56 gears sitting in the garage… just waiting until after the holidays to have them installed. I figured if the Recon has them with 35’s then why not?? LOL
 
The gearing will be a preference more than anything. I have 35’s with the 3.73 and no complaints. My 2012 had 4.10 with 35’s and still manageable in Colorado throughout the western states. It also had the 5 spd auto. The 392 has more than enough power to turn 35’s with the 3.73 Along with tighter gearing on the 8 spd tranny.
personally, I didn’t like everything with the recon package, except the gearing and speed governed at 110mph. The gearing I can change easily enough if I ever want to go that route.
after the tires, Tazer, calibration, I’m solid where I am with my set up.
also, some prefer 3.73 for some fuel savings. Others want 4.56 for better torque. In the end, it‘s preference.

Now, if I were to go to 37’s, I would swap to 4.10 at minimum. While I’m in there, I would most likely go to 4.56 just to retain the torque, as that’s the WHOLE reason I bought a 392.
I’m even researching super chargers now. Horsepower is my addiction. Women and horsepower. Both expensive and will make you cry or laugh at some point.

somewhat unrelated, One other aspect I liked with the Recon, was the speed limiter at 110mph. However, I also had a GC SRT and regularly cruised at 90-100. Pushing past 85 in the 392 Rubi, is plenty enough. At 100, it’s a bit intimidating, and honestly, in my humble opinion, if I wanted speed, I would have kept my SRT.

back to gearing...
the simple questions only you have the answer to.
you want to save gas? Lower RPMs.
or, do you want more torque? Higher RPMs.
 
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The Livernois tune will remove the speed limiter. I’ve been up to 102mph and it does get a little scary at that speed.
 
The gearing will be a preference more than anything. I have 35’s with the 3.73 and no complaints. My 2012 had 4.10 with 35’s and still manageable in Colorado throughout the western states. It also had the 5 spd auto. The 392 has more than enough power to turn 35’s with the 3.73 Along with tighter gearing on the 8 spd tranny.
personally, I didn’t like everything with the recon package, except the gearing and speed governed at 110mph. The gearing I can change easily enough if I ever want to go that route.
after the tires, Tazer, calibration, I’m solid where I am with my set up.
also, some prefer 3.73 for some fuel savings. Others want 4.56 for better torque. In the end, it‘s preference.

Now, if I were to go to 37’s, I would swap to 4.10 at minimum. While I’m in there, I would most likely go to 4.56 just to retain the torque, as that’s the WHOLE reason I bought a 392.
I’m even researching super chargers now. Horsepower is my addiction. Women and horsepower. Both expensive and will make you cry or laugh at some point.

somewhat unrelated, One other aspect I liked with the Recon, was the speed limiter at 110mph. However, I also had a GC SRT and regularly cruised at 90-100. Pushing past 85 in the 392 Rubi, is plenty enough. At 100, it’s a bit intimidating, and honestly, in my humble opinion, if I wanted speed, I would have kept my SRT.

back to gearing...
the simple questions only you have the answer to.
you want to save gas? Lower RPMs.
or, do you want more torque? Higher RPMs.
Great perspective and points! Thanks! The 4.56 rear gear ratio and max speed limit are indeed why I opted for XR package.

Something off the topic, I always wanted to own a GC SRT but was concerned for winter snow ride so I chose the GC summit and have been driving it for over 6 years. I’d love to hear how you feel the 0-60 between the GC SRT and your rubicon 392?
 
Great perspective and points! Thanks! The 4.56 rear gear ratio and max speed limit are indeed why I opted for XR package.

Something off the topic, I always wanted to own a GC SRT but was concerned for winter snow ride so I chose the GC summit and have been driving it for over 6 years. I’d love to hear how you feel the 0-60 between the GC SRT and your rubicon 392?
I feel the rubicon is slower. The SRT was tricky in snow, but proper tires would help. I also had some mods to the GC SRT. I was getting 0-60 in 4.1-4.2 consistently, without using launch. The “snap” the SRT had off the line pinned you in the seat. The Rubi just doesn’t have that. Smaller tires, engine mods, weight reduction, all play a part.
I still prefer the Rubi.
Also, the Rubi isn’t as quick as my BMW M340. That is quicker than the SRT. 0-60 in 3.9/4.0. Different altogether and twin turbo.
 
I feel the rubicon is slower. The SRT was tricky in snow, but proper tires would help. I also had some mods to the GC SRT. I was getting 0-60 in 4.1-4.2 consistently, without using launch. The “snap” the SRT had off the line pinned you in the seat. The Rubi just doesn’t have that. Smaller tires, engine mods, weight reduction, all play a part.
I still prefer the Rubi.
Also, the Rubi isn’t as quick as my BMW M340. That is quicker than the SRT. 0-60 in 3.9/4.0. Different altogether and twin turbo.
Thanks for sharing. You have really nice rides! I have another Audi A4 B9 that I drive couple days a week, even though the 0-60 takes over 5 seconds , it still feels faster and sportier than the 392 I test drove. My GC summit 3.6L is definitely underpowered, it’s a nice family SUV. The 392 XR be my first wrangler and I think it’s much cooler than my other rides.

Enjoy!
 
Great info. Thanks. I'm not after the massive torque that I think the 4.56 would bring. I could not be more pleased with the performance of my current setup. I am also of the 0opinion that above 80-85, the JL can be a bit unnerving. Not my driving, per se, but if I were in need of a quick and unexpected avoidance maneuver at that speed, I'm pretty sure I would need to clean the driver's seat. :cool:

I have a BMW M240i that I can use to hit the 100+ (and then some) mark. That one, though, does not do rocks, streams and snow all that well.

Thanks again for the support and opinions. Cheers.

Dan
 
From my understanding at least people with the 3.6 L Pentastar we’re having issues with the automatic not staying in seventh and eighth gear. The automatic with larger tires was constantly searching for power in the lower gears. People were worried that their transmission may go out prematurely. The 4.56 gears was supposed to solve that.
 
From my understanding at least people with the 3.6 L Pentastar we’re having issues with the automatic not staying in seventh and eighth gear. The automatic with larger tires was constantly searching for power in the lower gears. People were worried that their transmission may go out prematurely. The 4.56 gears was supposed to solve that.
That was my issue with 37 inch mud terrains and 4.10 gears. Any incline in the highway, and the trans would need to downshift to keep up with traffic. Much worse when fully loaded with camping gear.
 
Very interesting to read other 392 experiences. So far, with the 35's, I have not experienced any issues with hunting for the correct gear and power transfer seems very solid. Thanks for your input. Cheers.

Dan
 
First things, first. Love my 392. Lets get that out of the way. So happy with my decision. Bronco/Range Rover who???

I have a 2021 392 with 3.73 rear end. Took delivery in June of 2021. As soon as I took delivery, I swapped out the BFG KO2 33's for BFG KO2 35's. I am very happy with the ride quality noting that the 35's seem to provide a bit more of a "squishy" feel than the 33's, but not by much. I did not recalibrate yet and just note the speed and RPM differences while driving.

I guess I have a couple of questions?

  • Has anyone experienced any issues swapping out to the 35's? If so, what are your experiences?
  • The rear end is the 3.73 and with the new Recon, they have upgraded to the 35's but changed to 4.56 rear end. What does this change bring to the mix? Why is the 4.56 preferrable? Or... is it?

Clearly, the new Recon has some cool stuff that we all wish was on our original 2021's, but to me, all mods are now up to us rather than Mopar, which is more fun anyway. One thing I just did order was the Mopar fender flare extensions. They look pretty cool and will cover the extra width (not that this is a legal requirement here in NH). They are backordered forever, probably, but I'm a patient sort.

I have a few more mods in the works (winch, primarily) and once I hit 10K, I'm going to pull together all of my thoughts and post them for review. Right now, there are a few things eating at me...

  • The drip rails on the side roof lines seem to drip right into the front door when open. Ill conceived design.
  • Fuel tank needs to be a few gallons bigger (5 more would be great). Range is limited, even at 14.7 MPG. She never misses a gas station, that is for sure.
  • Steering, as many have mentioned, is not tight or precise - or even close. Would love to figure that one out.

Thanks for any thoughts. Wishing all my fellow 392 riders a Happy New Year.

Dan
"The drip rails on the side roof lines seem to drip right into the front door when open. Ill conceived design." Thanks for posting. This is my first Jeep and I was thinking "is anyone else getting cold water dripping inside their Jeep and onto their pants leg every time they open the door in the rain?"
 
"The drip rails on the side roof lines seem to drip right into the front door when open. Ill conceived design." Thanks for posting. This is my first Jeep and I was thinking "is anyone else getting cold water dripping inside their Jeep and onto their pants leg every time they open the door in the rain?"
I saw an instagram from a company, thatfineshop.com, made a product for that. I have no info on it or the company other than seeing they have a 'diverter'.
 
I saw an instagram from a company, thatfineshop.com, made a product for that. I have no info on it or the company other than seeing they have a 'diverter'.
This should probably be a separate thread.
 
Very interesting to read other 392 experiences. So far, with the 35's, I have not experienced any issues with hunting for the correct gear and power transfer seems very solid. Thanks for your input. Cheers.

Dan
I have 37x13.5 on 20’s. Very heavy set up. My 392 was searching for 8th and down shifting quite a bit to 7th and 6th at higher speeds. It would eventually get into 8th even at 85mph which pleasantly surprised me but it would never stay for more than a minute or 2. Regeared to 4:56 and it hardly ever down shifts out of 8th and it never needs 6th on the highway. Gas mileage is really no different depending on how I’m driving. I always hang around 11.5, sometimes better sometimes worse but after 2 months of regear I’m still at 11.5 today. Feels more responsive in the mid power bands for sure. As a side note, I can chirp the tires pretty good now doing a brake torque launch, it wouldn’t do that before the regear. Just my 2 cents…
 
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