It a 09 auto with 3.73. Gonna be running 35s. Did as much research as I could and everybody is really different. I will be doing alot of city/highway driving and some off roading. not rock climbing just mud and trails. So I was looking at 4.88 or 5.13 but read 5.13 tend to break. And I don't have a chip just planed on the aev procal. Please help. I am thinking about doing gears first before I lift and put wheels on.

 

Check this out, might point you where you want to go.

Alot of people will tell you go with 4.88, 5.13, or 5.38

 

Thats the problem. Is says 5.38s so why would people go lower?

And would 5.38 fit in a Dana 30?

 

I assume this charts tire sizes are based on actual measured tire heights? So most 35s you would wanna look more at the 34 in tire part?

 

People have different preferences/tolerances/opinions. I started with 3.73, went to 5.13 and ended up at 5.38. For me, 5.38 is the right gear for 35's. Whether I am up in colorado, or down in texas, the 2500-3000 rpm range gives me the best freeway performance. Lower rpm's, I can't hold speed or start dropping out of OD.

Many people like 4.88's, and feel that they give great performance. Could be that they have lighter rigs and live down at sea level, or maybe they just have no reference to compare 4.88 to 5.13/5.38?

I suppose your best bet would be to try to find someone local with an auto and these gears and see if you can go for a test drive. Maybe throw a post in the Staging Area for where you live.

And yes, there are some 5.38's for D30's, though I haven't actually read of anyone using them yet. With an auto and a light foot, I doubt they would be much weaker than 5.13's, but no feedback on it.

 

Hello everyone. I hve Diablo Predator tuner, JK 2007 rubicon, auto.... So I got tuner from Ripp SC.... There is only tire size setting and no gear ratio change. So I surfed the net and came out with the statement that there is no need to change ratio since you set tire size..... So this sounds rational to set ratio for tire or set tire to ratio..... Is it OK?

 

i'm running 5.13's on almost 33's and i tell ya i'm glad i made the move, shes peppy when i need it and running how i "feel" she should droppping out of OD when i want it to. i'm currently getting about 19mpg and usually drive about 67mph which is about 23-2400rpm's. I been driving cross country and all the mtn passes have been a breeze(sometimes shutting the OD off). wouldn't change a thing however i know i'm gunna be looking to move further with the build and i'm sure 35's will be in order at some point, the 5.13's should still be okay but i'm sure the heavier tires will slow me down a bit.

i'm pretty sure the 5.35's won't fit in the dana 30 because i prolly woulda did it straight from the get go and went to 35's a year and 1/2 ago when i did the initial modding.
just my opinion...

 

I have a 6spd w/ 315 75 17 and 4:88's. I think they are perfect. The reason I went with the 4:88's is that the pinion has 2 teeth intact with the ring at any time. with 5:13 there is only one tooth making contact and if I ever go with bigger tires I am afraid of of a large breakdown. as that is a lot of rotateing mass on one tooth.

 

I am leaning more towards the 5.13 and with the only one tooth in contact is scary but is there people on here that have actually broke them?

 

Richmond makes 5.38s for the D 30 and they are quality gears, they are the same size ring and pinion as 5.13 just different tooth count. Jeff at Just Differential told me about them and he was totally right. I was originally worried about RPMs on the highway being too high, but they are fine. I run 35" Pitbull Rocker Radials and the gears did wonders for the drivability.

I run some rough trails in the mountains with lots of rock, mud, roots etc. and they have performed flawlessly so far. I will say this is currently my DD and so I don't hammer on it. If you are planning on running 35s or better then go with 5.38, there is no reason not to. 5.38 is the new 5.13, which is the new 4.88