flyerfan033

First off I am looking to regear my 3.21 in my 2 door sport for either 4.10 or 4.56.

I test drove my friends Rubicon that has 4.10, we have the same size tires. The power is perfect and it drove completely different than my Jeep. So my question is....is there any difference in feel/power driving my friends rubicon with 4.10 gears verses what I would feel if I put 4.10 gears in my sport? I was not sure if there would be a difference because of the transfer case ratios.(4:1 vs 2.72)
I do understand that in 4 lo, his rubicon would crawl better, but while in 2 hi, would they also drive differently?

Thanks in advanced.

TOTL Innovations

No difference when in 2wd as that is just 1:1 no matter the transfer case you have.

anvil15

No difference in 4Hi either; both transfer cases have 1:1 ratio in high range. Only in 4 Lo will you see the difference, with the Rubicon having 4:1 and your Sport transfer case having 2.72:1.

flyerfan033

that's exactly the answer I was looking for. Thanks for the quick responses. Learn something every day!

BFGMallTerrains

Before you go to 4.10's please hear this: go 4.56 if you even THINK about tires bigger that 32"! I've now got 34" (which BTW fit perfectly on my stock Rubi rims with no spacers) BFG KM2's, look is awesome, and regeared from those pathetic 3.21's to 4.56 and found perfection. Lots of power and still in decent rpm range. Even improved mpg if anyone cares about that. Thought I heard angels singing upon hitting the throttle after this setup

Waldo_88

Not trying to hijack, but also before you re-gear, think about the strength of your axle components. The lower the gear ration (higher the number) the weaker the teeth become. In a D30 especially. Honestly, I wouldn't put 4.56 in a D30 if you're going to be running 35's or bigger. (Not that I would suggest wheeling bigger than 35's on a D30 anyways.)

BFGMallTerrains

Forgot to mention the metric size of my 34's as 305 70 17. Yeah I wasn't comfortable going 35 or bigger tho my off-roading consists of mall parking lots

twinz33

I ran 4.88's in my d30 for two years (open dif) on 37s, thousands of miles and zero problems. The axle is currently on a 2 door that gets wheeled often and still going strong. Easy on the skinny pedal goes a long way

Offroad_Elements

X2, ran a D30 4.88 on 37" Mud Grapplers, Aussie locker in it, with a Rubi T-Case... The D30 really will take a good amount of abuse, just know the limits, and easy on the skinny pedal! I had upgraded to a 60 a little over a year ago so I could romp it a little harder.

anvil15

Choice of gear ratio and tire size depends on your goals. As tires get taller, you need to perform more other modifications to keep reliability. Personally, I am happy with stock 32" tires and 3.73s with the 4:1 transfer case. Jeep put together a good package, with much bigger tires than in the "old days" but some just have to do more. Even if Jeeps came with 37" tires and 5.43s, "everyone" would argue that they "need" 40" and 6.14 gears.