Baystate Jeepers

I am unsure of what gearing to run with my 35"s and ATX slabs. They weight about 100 or so lbs 30+ over stock and I have 3.21 gears now, first is deep enough city driving is ok but the hunting and rather low highway rpm's are not. I am thinking of 4.56 4.88 or 5.13 anyone have any experiance with the 3.6l auto?

I'm at 4.88 with 35s in a 4.0

Im at 4.56 wishin I had 4.88s with a 4.7 , a 4 speed , and a 4x1 T-Case. So in low range its totaly awesome. I had said in another post for you to check a Tire/Ratio chart. I went from 3.73s to 4.56 but at the same time went from 32" to 35" and added only 300 rpm in high range. Trying to balance DD and wheelin is where you may have to make your choice. Id go one gear set over stock rpms for the tires you have or are planing to go to. 2 ratios at best to keep it streetable . FjR68

Frank wrote:Im at 4.56 wishin I had 4.88s with a 4.7 , a 4 speed , and a 4x1 T-Case. So in low range its totaly awesome. I had said in another post for you to check a Tire/Ratio chart. I went from 3.73s to 4.56 but at the same time went from 32" to 35" and added only 300 rpm in high range. Trying to balance DD and wheelin is where you may have to make your choice. Id go one gear set over stock rpms for the tires you have or are planing to go to. 2 ratios at best to keep it streetable . FjR68

What climb is that in your picture?

4.88s will make your MPG better and cause less strain in the drive line. The RPMs will seem a little high at first when you're on the highway, cruising, but it will put the engine in the sweet spot for getting you around. The V6, especially the 3.6L, likes a little more RPM than Jeep wants it to have, so you're goal is similar to stock gearing + a little extra.
4.56 is the LOWEST I would go.
5.13 is a little much but right around where you need to be for 37s. A friend has 37s and 5.13s on his 2008 auto and it is just a little more gear than a stock rubi on stock 32s with stock 4.10s. He's knocking down 18-20 mpg on the highway, but his total average economy is around 17mpg.

mrfreakinwhite wrote:4.88s will make your MPG better and cause less strain in the drive line. The RPMs will seem a little high at first when you're on the highway, cruising, but it will put the engine in the sweet spot for getting you around. The V6, especially the 3.6L, likes a little more RPM than Jeep wants it to have, so you're goal is similar to stock gearing + a little extra.
4.56 is the LOWEST I would go.
5.13 is a little much but right around where you need to be for 37s. A friend has 37s and 5.13s on his 2008 auto and it is just a little more gear than a stock rubi on stock 32s with stock 4.10s. He's knocking down 18-20 mpg on the highway, but his total average economy is around 17mpg.

That sounds pretty great. I got 17 MPG and under highway average with my stock gears doing 60-65. I need to figure out when to do the gears. I might as well do lockers and maybe a front axle at the same time. It's like 2600+ labor for the gears and lockers though....

On a JK D30, I would want good shafts and a selectable locker, like an OX.
$2600 - a drop in the bucket.

mrfreakinwhite wrote:On a JK D30, I would want good shafts and a selectable locker, like an OX.
$2600 - a drop in the bucket.

I was thinking it may be worth wait and doing a prorock 44 front axle. Any more jeep mods means no MV Agusta F3 this year