If i want to go with 35" tires do I need to change to 4.10's, it automatic aswell

 

I thought it had been established that the autos already had 4.10's.

The correct answer is absolutely though.

 

And I agree with Bob. 5.13 will be MUCH better. It will still dog with 4.10's.

 

'08 Autos have 3.73's standard. No optional 4.10 that I know of. I think the only way to get 4.10 is to get a Rubi.

Not sure about the '07's.

I think '09's will be the same way.

I think 5.13's would be overkill for 35's wouldn't it? 4.88 would probably be perfect. If you think you'll go to 37's later, though, you might go ahead and deal with the extra low gearing of the 5.13's with 35's to keep from needing to regear later again.

EDIT: Actually, according to this (http://www.4lo.com/calc/geartable.htm) chart, the 4.10's would be a good regear if going from 3.73's/32's to 35's. I further standby the feeling that 4.88's would be a good choice and probably still leave room for 36-37" tires later.

 

the way I always understood it, 5.13's are perfect for an auto with 35's.

4.88's manual with 35's

 

do a search and this will all clear up...

In 2007 you could get 4.10's with any model...

in 2008 4.10's are only available with the rubicon.

3.73 and 3.27's are in the X model and sahara...


Also 5.13's is adds a little pep with a 6 speed and 35's. I run this combo and it is perfect IMO. I would say its split between 4.88's and 5.13's on the board...

 

So with 3.73 gears whats the max tire diameter I can go with, basically street looks, not too much off roading around here. 33x12.5R20 or 325/50/22

 

So if I have an '08 Rubicon, I have 4.10s. If I want to up to 35s do I need to up my gears as well to 4.88 5.13? I have a standard transmission.

 

you dont HAVE to.

i have 35s and run with 3.73s. its survivable.

 

I have an 08 X, D44 rear, with 3.73 gears and 35" tires. It's also an auto. I noticed a significant difference when I put on the 35's. Unless I am on the freeway doing 65mph or more, I don't use overdrive. In fact, it is now a habbit for me to turn o/d off as soon as I start the Jeep. I will be going to 4.88 gears shortly, but for now, with o/d off, it's livable. I actually don't really mind it all that much, of course I haven't driven a Jeep with 35's with lower gears either, so I have nothing to compare it to. On take off, the Jk, when compared to a TJ (had one that I traded on JK) is a dog anyways. It takes a while for the torque to come up on a JK as opposed to the TJ. This was the first thing I noticed when I drove my JK for the first time at the dealer. Point is, if you do a lot of city driving, the 3.73 auto with 35's is okay until you can get your gears swapped. If you do a lot of highway and/or hill driving, it will be a little hard on the tranny unless you just leave the o/d turned off. Even then, it will kind of suck.