mook8651

Does anyone have 4.56 gears running 35's with the 3.8? Need some advice I'm either going with 4.10 or 4.56. It my DD an I drive 52 miles round trip to work everyday so don't want to go to step I am going I be pulling a small tailer for camping. I have a 6speed. I currently have 3.21 avg 17-18mpg now looking to stay around that. This is why I'm having a hard time to decide on gears. I know 4.56 will be cheaper but will it be to much

JKphotoshoot

My jeep is a auto, with 5:38's and 37's. It runs 2420 rpm at 70, makes it feel like it was back when it was stock. Still gets 14mpg around town and 16-17 interstate.

The 3.8 seems like its running a lot better in that rpm range. So as long as the Ratio you decide doesn't put you up over 2500 at 70 I think you would be ok.

mook8651

Right now at 70 in 5th I'm at 2000rpm 6th is pretty much useless unless going down an even when doing that 70-75 in 6th is around 1500-1700.

On the highway I'm usually in 4th at 2500 running about 60-65 an I'm ok with that I just want something where I don't constantly downshifting at every hill an have full use of my 6spd

JK Inspired

Running 4.88 auto 2.8 with 34s-2000 @60mph

mook8651

Currently I'm running 35's trail grapplers an plan on staying with them when then need replaced. Great tire all around an so far wear like iron

Ncb

4.88 would be best, but don't go less than 4.56. I have 4.88 (6 speed) with 35 and at 70 mph I'm in the upper 2K range. 4.10 would be a waste of money.

mook8651

I just don't want to put gears in it an regret it cause there to steep. I just want to have a I useable tranny again an not kill my mileage.

Also I want to be able to use 4hi instead of 4lo always. With 3.21 an 35's in 4hi it really sucks an its hard on the clutch when trying to wheel

nthinuf

Measure your tires (measured, not mfg's spec height!!) and start plugging numbers into the chart in the faq's. (stickied to the top of this modified area). This question is asked quite regularly, so there are a few hundred threads worth of opinions on what to go with, but your best bet may be to see if you can locate someone close to you who has the same size tires and has regeared, and see if you can go for a ride.

And you can generally disregard the advice given by people with the other transmission, since they have different gearing needs.

mook8651

Yeah I measured when they were new an they were around 34.5-34.75 from what I can remember. Now I'm not sure I'm going to guess around 34".

So either 4.10-4.56 would be good def don't want 4.88 just don't know if cost of 4.10 would be worth it an if I would notice that big of a difference in mileage between the two since the 4.56 are a few hundred cheap for the R&P

TJM12

I have a 6spd 3.8 with 4:56 gearing. I currently run 33inch nitto trail graps which are heavy. I also have lots of other heavy mods too. At 70 mph in 6th gear I'm turning about 2700ish the power and feel is great in every gear. I'm gonna go with 35's soon and I'll bet I will still be around 2400-2500 rpm @ 70mph. If you wanna go larger than 35's at some point or have an automatic then deeper gearing would be required but 4:56 is perfect for the 6spd 3.8 that is also a daily driver.