I just got my 35 12.50 17 tires. I I'm pretty sure I have 4:10 gears now, 2007 Wrangler x Auto, but this gear ratio is not working for me what is working for you guys running similar tires?

 

Try 5.13.

Some people living at sea level with no hills are liking 4.88, and many people with elevation changes in their daily driving are liking 5.38. (need a front d44 for 5.38's, they stopped making them for the d30).

Open the faq's and plug some numbers into the chart. Use measured tire height, not mfg spec. To get OD Off rpm, divide by .69.

And are you sure you have a d44 rear, and you're not one of the lucky '07 owners with a d35?

 

After almost a year of reading threads and asking questions it seem that 5.13 is the way to go with the 3.8L and 35's. I'm in the process of gathering up all the required tools for the job. I can't wait to finally get this done

Sent from my SGH-I337M

 

No I'm not sure. My stickers have all been painted over. I read on a Web site that all 07 Wrangler x w/Auto has 4:10 gears. And my superchips trail dash is saying I have 4:10s

 

Go to Jeeps website. In the For Owners area, dig around for an email address. Enter your info and the VIN, and request a build sheet. That will verify the axles and the gear ratio it shipped with.

If you have 3.21 instead of the 4.10's, you will need a new front carrier when you regear. If you were one of the lucky guys with a rear d35 ...

 

We went with 4.88's for our 35's,worked awesome for us.Now running 37's with the same gear set-up only kicks out of overdrive on some hills but liveable

 

That is probably the most noticeable impact of picking a gear ratio from choices are numerically close: how frequently you can't cruise in OD particularly on hills and a slight difference in fuel economy.

I ran the 5.13s with 35's and 3.5" lift and used the OD 90-95% of the time. But when I bumped up the lift to 4.5" it dropped down to ~80%. I could not cruise above 75 MPH in OD due to increased drag.

 

4:10

Auto with the 3.6

 

I have 4.88 gears in mine. Big improvement over the 3.73 I had. I am very happy I get a lot better gas milege and it stays in OD most of the time now.

 

2010, 35s, automatic. Switched to 5.38 from 4.10, was disappointed in the power change. 4.10 and OD off drove better than 5.38 and OD on around town and I still feel like I'm lugging the engine in 4th.