Forums
New posts
Search forums
Image search
Shop
Amazon Store
T-Shirts
Stickers
Members
Current visitors
Supporting Member Upgrade
Sponsors
About
Log in
Register
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Image search
Search
Search titles only
By:
Search titles only
By:
Menu
Install the app
Install
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Site Related
New Member Welcome Area
Hello everyone
Reply to thread
Message
<blockquote data-quote="Vman" data-source="post: 443972" data-attributes="member: 22091"><p>I have an 07 3.8 auto...so same as you basically. Mine has a dana 30 front diff which I think all the "x's" have, and is a 4 door unlimited.</p><p></p><p>There's a few things working against you with an 07-11: 4 speed automatic transmission, the 3.21 or 3.73 gearing in the diffs, a little less horsepower from the 3.8 compared to the 3.6, and for the non-Rubicons the dana 30 diff in the front.</p><p></p><p>Once you start throwing on larger (heavier) tires, the gearing in the diff and the shift points for the 4 speed get really bad. Even with 35's my JK would struggle going up a grade/hill and the transmission was shifting all over the place. I'd have to turn off overdrive to stop it from going bonkers going up a hill. Putting 37's on a dana 30 is a lot of weight that could break your axle just hitting a pothole.</p><p></p><p>Here is a great link to compare the size of tire you want to run, with either auto or manual, and if you're running a 3.8 (07-11) or a 3.6 (12+) JK. Blue would be a trail only rig, green is fine for highway driving, and yellow is underpowered and bad for both. It lists what your RPM's would be at 70 mph I think.</p><p></p><p>[URL unfurl="true"]https://prodigyperformance.com/blog/jeep-wrangler-gear-ratio-calculator/[/URL]</p><p></p><p>I can say that my '07 unlimited x (sport) on 35's with 5.13 gearing runs great. Transmission shifts naturally, you don't get the loss of power feeling, and the RPM's at all ranges are not a problem.</p></blockquote><p></p>
[QUOTE="Vman, post: 443972, member: 22091"] I have an 07 3.8 auto...so same as you basically. Mine has a dana 30 front diff which I think all the "x's" have, and is a 4 door unlimited. There's a few things working against you with an 07-11: 4 speed automatic transmission, the 3.21 or 3.73 gearing in the diffs, a little less horsepower from the 3.8 compared to the 3.6, and for the non-Rubicons the dana 30 diff in the front. Once you start throwing on larger (heavier) tires, the gearing in the diff and the shift points for the 4 speed get really bad. Even with 35's my JK would struggle going up a grade/hill and the transmission was shifting all over the place. I'd have to turn off overdrive to stop it from going bonkers going up a hill. Putting 37's on a dana 30 is a lot of weight that could break your axle just hitting a pothole. Here is a great link to compare the size of tire you want to run, with either auto or manual, and if you're running a 3.8 (07-11) or a 3.6 (12+) JK. Blue would be a trail only rig, green is fine for highway driving, and yellow is underpowered and bad for both. It lists what your RPM's would be at 70 mph I think. [URL unfurl="true"]https://prodigyperformance.com/blog/jeep-wrangler-gear-ratio-calculator/[/URL] I can say that my '07 unlimited x (sport) on 35's with 5.13 gearing runs great. Transmission shifts naturally, you don't get the loss of power feeling, and the RPM's at all ranges are not a problem. [/QUOTE]
Verification
Post reply
Site Related
New Member Welcome Area
Hello everyone
Top
Bottom