Please don't shoot me!!!

HuskerRubi

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Prospect, KY, United States
Ok, I have done a lot of research on gears. (This is my weak knowledge area on jeeps) :)

Just getting ready to re-gear and need one last little push before I go...

Need help deciding between 4.56 and 4.88's.

According to the charts and what i have read, 4.56's will put me in the green (stockish). 4.88's will still give me good mileage but more power than the 4.56's.

Thoughts?

I have an 06 LJR, auto, 35's, 3.5" RE lift

Thanks!

Mike
 
Pretty much everyone will say 4.88 here for wheeling, due to the auto.
Except for the 35" tires. I know it's not one of the choices, but 5.13 would be much better with the 42RLE & 35s.

4.56 would be a waste of money. Charts are guidelines, usually under estimated for real life.
 
5.13s with an auto 4.56 would be a waste of money

Sent from my SM-G930T using Tapatalk
 
5.38 is the way to go. 4.88 is not enough gear for 35's with the 42RLE transmission. My second TJ came with 35's and 4.88 gearing and it's an absolute dog on the highway with its 42RLE transmission. 5.13 is barely better than 4.88, 5.38 is definitely what I would go with.
 
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I couldn't find a 5.38 Dana 30 short pinion and then I caught that he has a Rubi so 44 F&R. Yea, 5.38's would be awesome in that case.
 
Thanks everyone! Apologize for my lack of knowledge, but what does 5.38's do for RPM on HWY, around town as well as gas mileage. Mileage is not my main concern, but don't want it to dip too low also.
 
Thanks everyone! Apologize for my lack of knowledge, but what does 5.38's do for RPM on HWY, around town as well as gas mileage. Mileage is not my main concern, but don't want it to dip too low also.


At 70 mph it would be 2495 rpm for overdrive (0.69) and 5.38 gears and 35" tires. In 3rd gear it would be 3615 rpm.
 
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Thanks everyone! Apologize for my lack of knowledge, but what does 5.38's do for RPM on HWY, around town as well as gas mileage. Mileage is not my main concern, but don't want it to dip too low also.

I can't help you with 35's and 5.38. But, I am running 33's and 5.13, with the 42rle.

B926DCC8-CADB-4DEF-BE05-8615136A62C1_zpszqnqhebi.jpg


So if you run 35's and are geared to 5.38, your speedometer and RPM's will be similar to what I am running.

Around town, that low gearing is quite awesome. And on the highway, I can easily pass others, and I don't have to struggle to when driving into the wind and going up hills.
 
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You aren't likely to lose much if any mpg. And it's very possible it may improve some since you are running the engine at a more efficient rpm.
 
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Let me know if you want pricing on a gear package. If you are not doing it yourself, have the machanic supply the gears and labor for no warranty issues.

Namaste,

Allen
 
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I can't help you with 35's and 5.38. But, I am running 33's and 5.13, with the 42rle.

View attachment 18040

So if you run 35's and are geared to 5.38, your speedometer and RPM's will be similar to what I am running.

Around town, that low gearing is quite awesome. And on the highway, I can easily pass others, and I don't have to struggle to when driving into the wind and going up hills.
That rpm with 35's is the minimum that is ideal for the highway, which is why I always recommend 5.13 or, better, 5.38. I personally hope to some day regear from my present 4.88 to 5.38 for my 35's and 42RLE transmission. 5.38 would barely give a slightly higher rpm than is in that photo which is really what you want for 35's with the 4.0L, 42RLE transmission, and with the Wrangler which is a fairly heavy vehicle... heavier than many people would guess. Especially given its barn-door aerodynamics on the highway. :)
 
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