JK Gearing and Lockers Advice

Do a search on jk-forum Dave from northridge4x4 responded to a few gear threads stating there is one company that produces all of the Jk gears with the exception of us gear who only makes 4.88s...Just make sure when you buy gears you buy from a "name brand" as they may all be made in the same factory but may not be made by the same specs

http://www.jk-forum.com/showth…light=northridge4x4+gears

took me a minute to find the thread with the best info in it

id say if u are gonna stay 35s go 488. if you are gonna run 37s go with 5.13. now it kinda depends on what size tires u pick. some are wider which will have more drag and some are true sizes and some arent. and as for lockers. def would be nice to have one in the rear with the 44. id dunno if i would put one in the 30 with tires as big as 37s, unless u beef up the 30 with some alloy axles etc. see if you can find someone selling a rubicon rear locker for cheap

Quote from GSE Nick

id say if u are gonna stay 35s go 488. if you are gonna run 37s go with 5.13.

Is that from direct experience in a JK or from a graph? Just curious.

Quote from GSE Nick

id say if u are gonna stay 35s go 488. if you are gonna run 37s go with 5.13. now it kinda depends on what size tires u pick. some are wider which will have more drag and some are true sizes and some arent. and as for lockers. def would be nice to have one in the rear with the 44. id dunno if i would put one in the 30 with tires as big as 37s, unless u beef up the 30 with some alloy axles etc. see if you can find someone selling a rubicon rear locker for cheap

Rubicon rear locker won't fit in a non rubicon housing.

If you are set on keeping the 30 the font of your rig I'd add some inner c gussets and sleeves along with some alloy shafts and control arm skids.

If you decide to go with a lunchbox locker you are stuck with the aussie unless you get a carrier from a tj/xj/yj. The JK carrier is a little wider internally and most lunchbox lockers won't engage properly.

My 30 is about as strong as you are going to make one(sleeves,gussets,open,alloys,3.73's) and I still don't trust it enough to run the trails I would like to run.

Quote from KnoxRents

Is that from direct experience in a JK or from a graph? Just curious.

ive drivin a couple 4 doors. one was manual with 35s and 488s and seemed to move pretty damn good.

Quote from GSE Nick

ive drivin a couple 4 doors. one was manual with 35s and 488s and seemed to move pretty damn good.

That's cool. I was just wondering. I did the graph thing which is a crock because I think it was made to suit a lower revving 4.0. I also did a gear ratio calculator and everything pushed me to 4.88's. ...but the higher revving, pig of an engine, 3.8 liter needs the lower gearing.

I kind of wish I went with 5.38's and my MTR's actually measure 34" so if he has truer 35's now, and plans to get 37's eventually, I figure 5.13's are a no brainer.

Geezuz.....5.38

Are there like 3 teeth on the pinion?

-Brad

Quote from KnoxRents

That's cool. I was just wondering. I did the graph thing which is a crock because I think it was made to suit a lower revving 4.0. I also did a gear ratio calculator and everything pushed me to 4.88's. ...but the higher revving, pig of an engine, 3.8 liter needs the lower gearing.

I kind of wish I went with 5.38's and my MTR's actually measure 34" so if he has truer 35's now, and plans to get 37's eventually, I figure 5.13's are a no brainer.

buddy of mine has 5.38s on his 4 door with 37 inch rockers. i havent drivin it but he said it still shifts in and out of OD alot. id like to drive it and really see how it does.

From what I read all over the tj inner c's ben. I would def do the gussets for them and yeah alloys are nice. Tossing money and time into it u might wanna gusset the whole thing with one from TNT. As for sleeves I'm curious as well. It's the only thing left to beef up my 44

And like I said with bigger tires like u are going I prolly wouldn't lock the front unless u had atleast shafts etc. That's just my opinion. Id toss a locker in the rear tho.

Quote from ruquik

Geezuz.....5.38
Are there like 3 teeth on the pinion?

Yeah. Just think. Here is the difference in my 4.10 and 5.13 pinions.

Quote from JKgray10

Should I do the axles the same time as the gears or is that easy to do afterwards? I do at least know its easiest to do the lockers along with the gears.

Doing a set of axles and keeping your stockers as spares is always a good idea but I bet you'd be ok running stockers.

Quote from JKgray10

I'm pretty sure I want something that isn't limited slip or can engage on its own. So pretty much I want something with a switch. I don't have any direct experience with using lockers but the biggest argument I hear is Air vs. Electronic lockers. I do like the idea of having an on board air system so it can be used for other than the lockers but I'm not sold on anything.

Air or electric is a lot of money. I would do a lunchbox locker in a D30.

Be careful spending a lot of money on that front axle. If you are like me, you may regret working on it just to realize you should have gotten something a little bigger. The fact that you want 37's is what makes me wonder.

A lunchbox locker is cheaper and goes into the stock open carrier in place of the spider gears. Lunchbox lockers are usually auto locking like a detroit would be. A JK lunchbox locker is around $300 vs an ARB that is $1000

I agree will Bill don't throw a bunch of money at the d30 if you want to run 37's. At the end of the day you would spend several thousand dollars and you still have an axle that isn't really up to the task.

Lunchbox locker:

http://northridge4x4.com/proddetail.php?prod=AL-XD-13227

You still need the 5.13 and install kit.

Upgrading to a 44 front is a whole new can of worms. The JK44 ring and pinion is substantially stronger then previous 44s and the axle u-joints are slightly larger then a d30. However a lot of people say it costs just as much to build a 44 front as it costs to build a 60 front. This is the decision I have been wrestling with.