So i got a 08 JK and traded in my old KJ. I bought it from an auction direct spot in Houston and got a pretty good deal on it. The lift, tires, and wheels are brand new (pro comp lift I'm guessing about 3 inch). On the test drive I was in houston and only got up to 55 mph or so because of rush hour traffic. So on the highway home I realized it absolutely will not pull in sixth gear at 70mph. I got my build sheet today from Jeep. It has the 3.21 gears and needs an upgrade badly. It is currently running 33" Nitto MT's. According to the chart on this site I should go to the 4.1 ratio for best overall performance and mpg's. So question is this. What do I have to buy in order to take to my mechanic? I've seen the ring and pinion set from several places online. Do I need to buy a rebuild kit also? Also which site is best (quality and value) site to go through? And, in the front what do I need to add (I've read something to the effect of a bracket of sorts if not starting with the 3.73 or larger). Oh yeah Dana 30 front 44 rear and manual transmission. Thanks in advance. Many more years of good wheeling coming as long as I can put it in sixth to get there!

 

Carrier for the d30
Two sets of gears (make sure they are for a JK, and that the fronts are not out of a rubicon)
Two master/overhaul kits (install kits can be used on low mileage axles, but you are better off with new bearings)

It is also the time to consider lockers/limiteds, C gussets, and possibly sleeves. You should also decide if you will be moving up to taller tires in the future. For the cost of re-gearing, you don't want to pay again next year for the new 35's or 37's.

 

Good luck with your new ride. Call Dave at Northridge 4x4. Tell them what you have, and they will sell you what you need.

 

Good advice, thank you,

I agree that it is time to take stock of things now and see where I want to go. If I were a die hard optimist I would look at this as a blank chalkboard thing...(not a glass completely empty scenario). So as it is, to give you a little background, this is my 3rd jeep. the first was a TJ I loved it till the tranny failed (Peugot or Renault). The replacement trans was never the same. The second was this one...

 

sorry didn't mean to submit just wanted to see if the pic worked... oops (notice the newbie status). At any rate what I was trying to say is that I have family all over the country, and it takes forever to get to Colorado from Louisiana so the JK has to be a traveler as well as a wheeler. I don't imagine I'll go to 35's in the near future. What do you think gearwise?

 

I have an auto, so absolutely no experience with the jk 6-spds, but I can't imagine paying over a grand (some people are paying over 2 grand, depending on area) to gear back to a stock ratio. Either leave it alone, or add a tuner, or go to 4.56's.

 

Everything listed for rebuild. 4.56s are ideal for all around performance. My buddy and I debated between 4.56s and 4.10s. 4.56s was the ultimate winner. Complete life change in the jeep. I will not tell you I drive a rocket ship because that is simply not true, but I will never complain about power from my 3.8. Love it. I baby the eff out of my jeep. 4.56s and a Procal. Perfecto. Yukon gears for me. Hope that helps.

 

I have a 09 Jk Unlimited 4dr. 6 speed manual. I recently upgraded from 32's to 35's and
can barely feel any loss of power or gas mileage. I also have a Screamin Demon Coil &
Live Wires.

 

For 33s I would go 4.10 if you plan in going 35s then go 4.56. I had 4.88 g2 gears installed in my jeep and it was $1k parts and labor.

 

went to see my 4x4 mechanic today. He felt 4.56 gears would be a little too much gearing for the 33's and that I would have best overall performance to mpg with the 4.10. On the bright side he has everything in stock and can do it next week. He also has a take off detroit locker for the rear he is going to throw it in free. All done and installed including sleeves and gussets for the front for $1500. Sounds fair to me. What do you guys think??