It seems like the new gearing will cost you about $400 - $500 per axle (that's for a shop to install them, which I believe is the preferred way to get them in there). From what I have heard, you can expect to get back out 2-3 mpg. Shift patterns are reported to be better as well. I don't remember hearing about and increase in power to the wheels, but it stands to reason that you would expect to gain just a bit.

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'06 Stone White, CRD Limited
CRD Frankenlift II, Rock Lizard Rear Bumper, Mann Provent, GDE FT-ECO Tune, "Euro Torque Converter, Transgo 545RFE-H2 Shift Kit, 245/75 MT/R's on Moabs, Full Mopar Skids, Front Tow Hooks, CAT 2 Fuel filter and bleeder valve mod, Fumoto valve, Wahlbro Lift Pump, Custom 2 1/2" Exhaust

Re-gearing the axles does not increase power output of the engine.

Any "perceived" increase in power is from the change in gear ratio to aid the KJ is lower speed ranges.

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02 Liberty Limited
Silver Outside & Taupe Inside
Heated Seats, Sunroof & Infinity speakers
USA Spec I-Pod adaptor, Mopar Sub, Garmin GPS
Tow Package, Select-Trac
Rock Rails, Tow Hooks

but re gearing puts more power to the ground after installing larger tires so in fact you do have more power to use, engine may not put out anymore but you will be using the power you have better

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

Regearing is like getting free power......................

Say your engine is putting out 200lbs-ft of torque at the crankshaft(just a # to make it easy,and using the 3:1 1st gear from the 45RFE),with 3.73 gears you are putting 2238lbs-ft of torque to the wheels,now take off the standard 20% in parisitic loss that's still 1791lbs-ft of torque.Now switch to 4.10's you are putting 2460lbs-ft of torque to the wheels,1968lbs-ft after parisitic loss.That is a total of 177lbs-ft of free torque to help move those taller tires.

great example tjkj

I have been regearing 4 WDs for 25 plus years and still find it amazing that people ask why do you want to do that or you never need to regear it doesn't help any or I have only gone from a 28/29 inch tire to a 32 , not that much difference that I can tell

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

I understand the mechanical factors behind the reason to re-gear.

I just don't like it when people ask how much power they will get by adding a shorter gear. There is not any power added to the system the engine still generates the same power, even if the KJ feels 500 pounds lighter.

_________________
02 Liberty Limited
Silver Outside & Taupe Inside
Heated Seats, Sunroof & Infinity speakers
USA Spec I-Pod adaptor, Mopar Sub, Garmin GPS
Tow Package, Select-Trac
Rock Rails, Tow Hooks

Actually the engine can produce "more" power,at least what it is supposed to at least.I your driving around with 32" tires and the stock 3.73 gears you are over stressing the engine and the rest of the drivetrain(trans),actually making the engine work harder which will over time make the engine produce less power(from wear).Regearing correctly can reverse this pattern.

Well I know that its not going to gain any HP. But like some one said it is going to put more power to the ground. For the price I dont think its worth it. I mean yeah 2-3 mpg would be nice but 1000 to get 2 mpg. Lets see thats 40 miles per tank extra. 40xgas price (1.80)=72. 1000/72= is about 14 gallons. SO it would take me about 14 gallons to get my money back to even break even. I figured a CAI would get me about the same MPG increas and cost way less so I will go that route if Iam gonig to put anymore money into the KJ. ANd please I dont want to hear the whole its more of a Hot Air Intake blah blah blah.

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Sure you may only gain 2-3mpg's,that is not the reason why you should regear when going to larger tires.The main reason is to keep the added stress from the bigger tires from trashing your trans and prematurely wearing your engine(shortening the life span).


HHHMMMM.........................

$1000-$1500 to regear

OR................


$5000 for a new engine and $3000 for a new trans



Tough choice.




Now if you are not keeping your KJ it's up to you but if you plan on keeping it for some time it's a worth while investment that will pay off in the end by having less "high" mileage problems.



Just my 2 cents.

But the engine runs easier and smoother with more of the correct gearing and I will not say anything about a CAI except from my own tests over the last 100,000 miles its hard to beat the stock box and a Amsoil filter, trust me tried them all and all you get extra with a CAI is more noise and thinking you are doing better.

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

4:10’s are next on my list. That’s if I can find them.

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2015 Ram Ecodiesel/Big Horn/4x4/Quad Cab
2016 Arctic Fox 22G/Onboard 2500 LP Cummins Onan Generator/160 Watt Solar Panel

I took the road less traveled. Now I'm LOST.

Yea, they're on my list too but a little further down . Maybe by the time they reach the top of my list they will be readily available.

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'06 Stone White, CRD Limited
CRD Frankenlift II, Rock Lizard Rear Bumper, Mann Provent, GDE FT-ECO Tune, "Euro Torque Converter, Transgo 545RFE-H2 Shift Kit, 245/75 MT/R's on Moabs, Full Mopar Skids, Front Tow Hooks, CAT 2 Fuel filter and bleeder valve mod, Fumoto valve, Wahlbro Lift Pump, Custom 2 1/2" Exhaust