Im running 35's on the stock sahara 18's. Sahara 2010 auto (3.73 gear ratio)

If i was going to re gear, what gears should I run? It does ALOT of highway driving (110km+), worried about a 5.13 being too low?

Any advice?

 

I think that my 4.88s with 35s are perfect. But, I have a six speed. With your auto, the rule of thumb is to bump it down to the next gearset--so 5.13s is the better answer. They are weaker, however, and with a D30 front axle that can be problematic. I'm giving my old axles (I installed chromolly axles a couple months back) to someone here in OK who trashed his D30 axle with 5.13s just yesterday. So, if you go this route, treat them gently.

 

How are 5.13 weaker gear talk confounds me still cause I'm looking at same issue as original poster

 

I'm running 5.13's on my JK with 35" tires, auto trans. What an improvement over the stock 4.10's I had. It's not that the new gears themselves are weaker but perhaps the higher gearing can put more stress on the axles from a dead start.

 

Measure your tires and plug the number into the chart in the FAQ's.

An auto JK on 35's simply can not be over-geared where rpm's are concerned. (hint: you will have lower rpm than a 6spd Rubi driving off the assembly line). The only consideration is your offroad usage. If you like to stand on the gas pedal while bouncing through the rocks, 5.38 or 5.13 may not be the right ratio for you.

 

4.88 is probably the more correct ratio for a set of 35's and, if most of your time is spent on the highway, they might be the better way to go. for me, i prefer 5.13 as it will help give you a bit more power especially on long hill climbs.

 

The 5.13 has less tooth contact area, i.e. higher stress per tooth due to the same force over a smaller surface area. Causes them to have a tendency to shear under sudden harsh loading.

 

Thanks for all the advice! Sounds like i should probably be looking at 4.88s. I do alot of highway/onroad, even though it sees the mud and rocks as often as possible (twice/three times a month).

Thanks again everyone.

 

I'm putting 35s on mine this weekend, with 5.13s. I wanted the extra torque for hills, and am planning on 37s in the next few years, so might as well gear for it now

 

I'm running the 5.13's with my auto and 35's. I commute around 100 highway miles each day....im still getting between 18-18.5mpg running 65-70mph....