I have a 2009 manual with 3.21 gears. I recently put 33x12.5x17 MTZ's on and am noticing that the jeep is extremely sluggish. I do mostly country road/highway driving and was wondering if regearing would help give me both lower and higher end power. I now rarely use 6th gear as it has no power on hills. If regearing would help, what's the right number?? I plan on adding a 3in lift and new bumpers at some point.

Thanks!

 

Yes, you will want to regear. Here's some good read: https://www.jk-forum.com/forums/modi...e-chart-98709/

 

x2 on the chart. Check it out. I have a manual also and I'm running 37s with 4.88 gears. It is perfect with a manual. I run country back roads all day and have no problems pulling 6th gear on the highway. Plenty of pulling power. If I was running 35s, like the previous poster I'd of gone with 4.56s. For 33s I'd go probaly go 4.10s...though I'm sure 3.73 would work. You'll have to get some opinions from others running 33s with a manual.
Either way you will need a new carrier because of your factory 3.21s as well as the gears and install/overhaul kits.

 

I have 33x12.5x15 duratracs with 3.73 gears and manual trans... Go bigger 4:10 at the min. Mine struggles on long hills maintaining highway speeds, I plan to regear to 4:88 or 5:13 when I upgrade to 35"

 

Gears will help if you have the extra $$$ sitting around. We run a 2010 JK with 35s and 3.21 and it's just fine, but no use of 6th gear unless we're doing 80mph or higher. To be honest it ran fine with the 32" KM1s on Rubi rims, so I'm suprised you even noticed much with the 33s. We wont regear unless we go up to 37s though, not much point otherwise. If you regear now because of 33s and you decide to move up to 35s or 37s down the road, you'll want to regear a second or third time. Think about that before you regear for 33s, if your end goal is to get bigger tires down the road.

 

I have 2011 MT with 33"x12.5x15 duratrac's and recently changed from 3.21's to 4.56 .. IMO the gearing for 33's is perfect. 1st thru 6th gear are useable, I picked up a decent amount of pep and I can now drive over the moutain passes of california by just leaving it in 6th gear instead of constantly shifting.Mpg's took a small hit in the city from 17.5 to now 16mpg but freeway I get a steady 18 mpg if I keep it around 70 mph. At 70 mph my RPM's are 2800 roughly. abit high but most on here say the 3.8L liked the higher rpm's?