re gear question manual trans

[callerys]

The Gen III D30 can handle all the way to 5.38 without swapping carriers like the JK.

Its a rubicon

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[JT1]

4.56s in 5th will have the same ratio as 5.13s in 6th. What gear do you find you need to climb on the highway? 3rd? 4th?

 

[Scott97]

Here are two gear carts I made when over thinking this same thing. Although RPM is important, torque is where it is at. You want to be around 200lb-ft and 2300RPM or higher. That is where the 3.6 gets up on the flat spot of its torque curve. The green shaded area on the chart tells the story. The more green the better. I agree with a previous post that sustained cruising at or below 2500RPM is best on the highway for both engine life and MPG. Credit to @AnnDee444 for the torque data, excellent thread back in 2020, did a great job averaging available torque curves, normalizing the data and generating a torque vs RPM chart. https://www.jlwranglerforums.com/forum/threads/3-6-torque-curves.62669/

 

[Scott97]

Doesn't look like the gear charts uploaded correctly.

 

[Stetson]

Doesn't look like the gear charts uploaded correctly.

That is pretty awesome comparison! Thank you posting

 

[callerys]

Doesn't look like the gear charts uploaded correctly.

Thank you!

 

[callerys]

Thinking either 4.56 or 4.88 based on the charts. May go to 35's later. I do a lot of highway driving and I had heard to keep in under 3k RPM most of the time to reduce wear on 2nd stage of oil pump. Not sure if there is any truth to that. If its not true then ya just bad gas mileage which is fine.

 

[grimmjeeper]

Both would be fine for 33s. 4.56 would be adequate with 35s. I had that combo in my JK in the mountains here in CO. I wish I would have gone to 4.88 for 35s. But the transmission had slightly different ratios.

With 33s, you'd probably be happy with either. If you want 35s, I'd lean towards 4.88s.

 

[azwjowner]

I have 4.56 with 32s, which is the same as 4.88 with 35s, and it's great. Would not go less or more.

 

[jbcrane]

Howdy neighbor from Fort Collins. +1 for 4.88's and 35's here in CO. I had Northridge in SLC do mine 3 years ago and never looked back. Great upgrade for the 6MT. First is a little short but you get used to it. I'm on a smaller, lighter KO2 for now but am well prepared for a heavier set of MT BB AT's coming soon.

 

[chevymitchell]

Its a rubicon

I’m aware. I was answering the other posters question.

Are you considering any other parts/upgrades when you regear?

 

[callerys]

Nothing right now. Plenty of tire left on these 33's. Gotta fix the diff service bogus issues as well as the broken swaybar disconnect wiring.

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