Proof 2012 Rubicons on 35s need 456 gears
#42
JK Super Freak
#43
I'm scheduled to go in tomorrow and pick up a new 2012 Rubicon with a manual transmission and w/o a tow package . They told me it has 4.10 gears as the salesman checked with the service representative. The build sheet doesn't mention any gear ratios. I looked up the VIN on the Jeep site, and it was blank. How can I verify they're telling the truth? I plan to run 35's soon.
#44
Disregard. I just went to the Jeep website and tried to build a new 2012 and it would not let me select 3.73 gears with a manual transmission. Apparently the 3.73 gears option is only for an automatic. Correct me if I'm wrong.
#45
JK Enthusiast
Join Date: Jan 2012
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I'm scheduled to go in tomorrow and pick up a new 2012 Rubicon with a manual transmission and w/o a tow package . They told me it has 4.10 gears as the salesman checked with the service representative. The build sheet doesn't mention any gear ratios. I looked up the VIN on the Jeep site, and it was blank. How can I verify they're telling the truth? I plan to run 35's soon.
#46
you may need to go to 4.56 to regain stock pep, but you don't need it to be drivable. I have 2012 Auto 3.73 and at 70mph I am at 2100 RPM. I am getting only about 1mpg less than when I was stock. I am a little slower than when I was stock but I still get on the freeway without any trouble.
I am sure once you get your 35's you can see for yourself if regaining that loss in "pep" is wroth the gearing change. I would recommend getting the lift and wheels first then decided if the next few grand you spend should be gears or if you can live with the speed and spend that on something else.
I am sure once you get your 35's you can see for yourself if regaining that loss in "pep" is wroth the gearing change. I would recommend getting the lift and wheels first then decided if the next few grand you spend should be gears or if you can live with the speed and spend that on something else.
#48
I agree with HypeIV...I think this is only proof that to have the exact same RPM's at the same speed then you would have to regear. Has nothing to do with driveability or NEEDING to have it done. They come with lower ratio's than 4.10 and drive and operate just fine.
#49
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I have a 2012 JKU with 3:21's and 35" tires and it drives fine so yeah you can spend the money to regear I plan on it when I upgrade my axles but I have had plenty of people tell me how much faster it is then re-geared 3.8 liter engines. So it is staying at 3:21 for now.
#50
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Why in the world Chrysler put 321's in a Jeep is beyond me... I just bought a 2012 and the plan all along was 35's. I could not afford a Rubicon so I has to scour the state for a Sport with 3:73s.. took a trip with my 35s. Hwy speed up to 65mph was ok but beyond that the engine had to work so much more to push itself against the wind the MPG would fall by the second. Wheeling in 4l is ok but in all reality 456s are on the short list... 3:21s were to keep the EPA happy with the total model year fuel economy. That's all there is to it
65 mph for a Jeep is not so bad though, is it? (Jeeps used to come with a four-banger...)
And then there's always the Grand Cherokee if you spend a lot of time on the autobahn LOL