4.88 gears versus 5.13 for 4 door auto jk
06-22-2011, 03:43 PM
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4.88 gears versus 5.13 for 4 door auto jk
I searched for a quick answer to my question, but good not find one. Which gearing would be better for an auto jk if I go to 35inch tires from 33 inch tires - 4.88 or 5.13? I currently have 3.73 gears. I have been told 4.88 is good, but is 5.13 better?
06-22-2011, 04:43 PM
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I have 35's and have had my 4.88's for about 30,000 miles now (with an auto). For me, I wanted to get the RPM's close to what was stock so that I don't wreck the gas mileage. I don't regret it at all. 
06-22-2011, 05:19 PM
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5.38's !!
Did you notice the RPM charts a few posts above yours? They are also in the drivetrain section of the faq's. Assuming you use the actual measured tire height and not the mfg's spec, they are pretty accurate.
This thread is a good read also. Start with post #33.
https://www.jk-forum.com/forums/show...=1#post2147185
If so I would like to know what your rpm is at 70mph? I'm curious how close my math is. From what I came up with this is very close to stock 32's with 4:10's about 200RPM.
This thread is a good read also. Start with post #33.
https://www.jk-forum.com/forums/show...=1#post2147185
Last edited by nthinuf; 06-22-2011 at 05:22 PM.
06-23-2011, 03:12 AM
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Yes, I have a 5'X10' utility trailer and haul firewood (and other stuff) with it. I only use it every now and then but it does fine with it.
I'll check the RPM's at 70 this morning on the way to work. I know the chart is up there so we can see how close it is.
I'll check the RPM's at 70 this morning on the way to work. I know the chart is up there so we can see how close it is.
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06-23-2011, 03:14 AM
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It's not a Rubicon, but it did have 4:10's. Yes, I did recalibrate my speedo. I'll check the RPM's this morning.
06-23-2011, 04:51 AM
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But isn't that using the 3rd gear ratio of 1:1? with overdrive, the rpm's will be less right? I'm just diving into the re-gearing swamp of opinions and posts and trying to get the facts. Thanks!
06-23-2011, 04:52 AM
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