gearing for 35's
JK Freak
Joined: Feb 2007
Posts: 648
Likes: 0
From: Birmingham, AL
Agreed. Go for the power of the 5.13s ... I did and I like it!
You will rev higher but the 3.8 engine's power band is more responsive in the 3000 range . The stock gearing runs the engine in the 2000 rpm range for each gear. My 6th gear actually has some pull now and it was practically worthless before when I had stock tires and 3.21s. So why would you want stock performance out of 4.88s and 35s? You could spend more money on other power adders and you wouldn't see the difference that the 5.13s would give you. Plus the 5.13s don't cost any more extra $$ than having 4.88s installed.
You will rev higher but the 3.8 engine's power band is more responsive in the 3000 range . The stock gearing runs the engine in the 2000 rpm range for each gear. My 6th gear actually has some pull now and it was practically worthless before when I had stock tires and 3.21s. So why would you want stock performance out of 4.88s and 35s? You could spend more money on other power adders and you wouldn't see the difference that the 5.13s would give you. Plus the 5.13s don't cost any more extra $$ than having 4.88s installed.
JK Super Freak
Joined: Sep 2007
Posts: 1,623
Likes: 5
From: Lawrenceville, NJ
If you don't have the money for tires, the money for re-gearing will be a similar stretch.
Based upon this info, I strongly recommend that you wait to re-gear.
After you get new tires, and see in your own experience how it drives, feels, etc....THEN you can take a fresh look at re-gearing.
My own take on it is that the lower gears are better, but, so are a lot of other things, like having money for food, clothing and shelter.
In the overall scheme of things, you may find that the larger tires and their change to your effective gearing, is not as big a deal as you thought.
You may also find that in the future, you want a locker, etc....and have to open a diff anyway. That's a logical time to take advantage of the diff being open anyway, and combine the diff work with new gears at that point, etc.
As far as hwy use goes...you'll be a few hundred rpm lower in each gear for a given speed....and sometimes, you'll be driving a 4th instead of 5th, or 5th instead of 6th, etc...BUT - it doesn't matter, as the tires are PART of your effective gearing ratio...so it doesn't matter what the shift pattern says...you are still going 60 mph at 3,000 rpm (Or whatever...), regardless of what combo USED TO do that for you.
As far as your gas gauge knows, its all business as usual...same rpm at cruising speed, what ever you used before.
Re-gearing now, IN CASE you get larger tires in the future, when $ is tight, really doesn't have any strong selling points.
Waiting to see how you feel about it in the future, when you HAVE the larger tires AND some seat time with them, and the $ to make adjustments, if still desired, has stronger selling points and, in your case, makes more sense to me.
Based upon this info, I strongly recommend that you wait to re-gear.
After you get new tires, and see in your own experience how it drives, feels, etc....THEN you can take a fresh look at re-gearing.
My own take on it is that the lower gears are better, but, so are a lot of other things, like having money for food, clothing and shelter.
In the overall scheme of things, you may find that the larger tires and their change to your effective gearing, is not as big a deal as you thought.
You may also find that in the future, you want a locker, etc....and have to open a diff anyway. That's a logical time to take advantage of the diff being open anyway, and combine the diff work with new gears at that point, etc.
As far as hwy use goes...you'll be a few hundred rpm lower in each gear for a given speed....and sometimes, you'll be driving a 4th instead of 5th, or 5th instead of 6th, etc...BUT - it doesn't matter, as the tires are PART of your effective gearing ratio...so it doesn't matter what the shift pattern says...you are still going 60 mph at 3,000 rpm (Or whatever...), regardless of what combo USED TO do that for you.
As far as your gas gauge knows, its all business as usual...same rpm at cruising speed, what ever you used before.
Re-gearing now, IN CASE you get larger tires in the future, when $ is tight, really doesn't have any strong selling points.
Waiting to see how you feel about it in the future, when you HAVE the larger tires AND some seat time with them, and the $ to make adjustments, if still desired, has stronger selling points and, in your case, makes more sense to me.
JK Enthusiast
Joined: Oct 2007
Posts: 299
Likes: 0
From: Oak Harbor, WA
Driving with larger
I haven't regeared and I'm going to. I'm running 4.10 with 35's which many will find accceptable. I stopped watching my Gas Mileage Computer and any of that a while ago but I deffinatly fill up more. It's only because I have to give more gas to get going, at highway speeds the RPM's are lower but traffic here sucks and it's stop go on the free way a lot. Anyone drive in VA?
I atleast want the same as stock performance so I'm re-gearing but I agree with what others have said, drive it first then decide. It's going to cost almost 1300 for me, since it's beyond my capability to install.
I atleast want the same as stock performance so I'm re-gearing but I agree with what others have said, drive it first then decide. It's going to cost almost 1300 for me, since it's beyond my capability to install.
JK Freak
Joined: Apr 2007
Posts: 628
Likes: 0
From: Northern New Mexico
Come on... we all should just eat/sleep/drink Jeep! j/k... TEEJ makes a good point here as do the rest. I think if you go to 35's or bigger, in the end you'll regear. However, get the tires first, worry about the gears later... especially if you have a manual. I have an automatic, so I don't have the luxury of having the options of 6 gears as a manual would so I made the switch right around the same time I did the tires.
JK Newbie
Joined: Aug 2007
Posts: 85
Likes: 0
From: Dubai - U.A.E
Well,
I was in the same boat when it came to re-gearing. I have the 07 Sahara 2 dr manual and she is now lifted and sitting on 35's MT-Baja Claws. I spent many many hours on the site reading and asking which gears will i need.
Got the JK after the lift and tires and i was shocked I thought i would of lost power due to the 35's but i feel no change. Now keep in mind i do have extra stuff like ( AEM Air intake, Boarla Cat-Back, JET chip stage 2 ) so i guess thats why i dont feel any loss. I still havent tested her on the trails which will be this friday 
So after many many searches i ordered the 4.88s and they are still in the box in my front room
I am still confusued But i am just waiting on what drive shafts to get then will get it all installed at once.
I agree with most here, you really need to feel how she drives after your add ons that way you can be the best to judge if you want to re-gear.
So as for me i think 4.88s on a stick will be amazing i hope
When i do install them then only will i know if i made the right choice. I will update on the 4.88s on a stick once i have done them.
The other reason i went for 4.88s was i kept seeing all stick owners going for 4.88s and running 35's and 5.13 running 37's auto. So i guess i have made the right choice. 
Plus i have no future plans for 37's
I was in the same boat when it came to re-gearing. I have the 07 Sahara 2 dr manual and she is now lifted and sitting on 35's MT-Baja Claws. I spent many many hours on the site reading and asking which gears will i need.
Got the JK after the lift and tires and i was shocked
I thought i would of lost power due to the 35's but i feel no change. Now keep in mind i do have extra stuff like ( AEM Air intake, Boarla Cat-Back, JET chip stage 2 ) so i guess thats why i dont feel any loss. I still havent tested her on the trails which will be this friday So after many many searches i ordered the 4.88s and they are still in the box in my front room
I am still confusued But i am just waiting on what drive shafts to get then will get it all installed at once.I agree with most here, you really need to feel how she drives after your add ons that way you can be the best to judge if you want to re-gear.
So as for me i think 4.88s on a stick will be amazing i hope
When i do install them then only will i know if i made the right choice. I will update on the 4.88s on a stick once i have done them.
The other reason i went for 4.88s was i kept seeing all stick owners going for 4.88s and running 35's and 5.13 running 37's auto. So i guess i have made the right choice.
Plus i have no future plans for 37's
Last edited by Jeep 007; Dec 12, 2007 at 02:36 PM.