2K1TJ

I know you were asking him, but I found the best gear ratio calculator ever a few weeks ago. It's very specific. You can enter your specific transmission (nsg 370, close ratio is the 6 speed in JK's , not sure what the auto is), your specific transfer case, gear ratio, tire size, basically every different variable you can think of. And it does the hard work for you. It knows all the transmission and t-case ratios.

Click here

Jasson

Hey Benmar2000,

Just curious, where did you find the info on the tranny gears?

Good find!

jeepik

im going with 4.88's for my Rubi on 35's i think it will be perfect with the 6 speed

mine will be dropped off at Offroad evolution on the 10th of paril, so Mel can do his magic

i think 5.13's and 35's are too low for highway usage, you will find that your jeep will be getting awful gas milage
the 4.8''s paired with 35's and the stock 6 speed, will put the jeep at a tiny bit lower ration then from the factory, which will give it a little bit more power

RedRockJK

Here's a quick comparison for an Automatic with 4.10 and Stock Rubi Tires vs 4.88 and 5.13 with 315/70/17 tires.

All RPM's are in Overdrive (4th gear)

4.10's with 255/75/17 (stock Rubi tires)
55 MPH = 1631 RPM
60 MPH = 1779 RPM
65 MPH = 1927 RPM
70 MPH = 2075 RPM
75 MPH = 2224 RPM
80 MPH = 2372 RPM

4.88's with 315/70/17
55 MPH = 1811 RPM
60 MPH = 1976 RPM
65 MPH = 2140 RPM
70 MPH = 2305 RPM
75 MPH = 2469 RPM
80 MPH = 2634 RPM

5.13's with 315/70/17
55 MPH = 1904 RPM
60 MPH = 2077 RPM
65 MPH = 2250 RPM
70 MPH = 2423 RPM
75 MPH = 2596 RPM
80 MPH = 2769 RPM

I think I'll be going with the 5.13's.

Puddlz

Thanks for the info Red Rock,

5.13's here too

Piginajeep

I see the gears are for sale on a couple of the sites, but no install kit,

Is it the same as regular D44's and D30's?

wayoflife

Nope. So far as I know, you need to reuse the existing components. But, since most of us only have a couple grand on the odometer, I would think it'd be okay.

jeffmarion

My installer said that the bearings will be fine, the only other thing he will need to install are the pinion seals.

Piginajeep

and what will the person need thats buying my gears, that has 3.27's now..

I dont have a clue

Northridge4x4

IMHO you will want a new crush sleeve also.

David