I decided to regear to 5.13 and install ARB locker on my JK.
My Jk is X model, front DANA30, rear DANA44, 3.73 gear ratio.
35 inch tire, 3 inch lift


No I need to finalize the order. I have many things need your
clarification/advice/suggestion:

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Gear:
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There are many brands of ring/pionion kit to choose:
Chrysler, USA, Superior, Yukon
which brand is the best generally?
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Do I need to buy overhaul kit or install kit?
The difference seems like:
Overhaul kit includes every install kit has PLUS pinion bearings and races, carrier bearings and races.
Do I really need them?
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When placing order, what do I need to tell to vendor?
Is the information I collected below correct?
front: DANA30, 5.13 ratio, Reverse
rear: DANA44, 5.13 ratio
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4.88 vs 5.13 issue
I personally prefer more power boost and not that much concerned
about MPG. Besides I want to leave room for 37 inch tire later.

But one thing bothers me is the strenghth of the 5.13 gear set.
From what I know, the higher the number, the thiner the pionion
and the smaller the ring gear teeth.

Most people seems to think JK's DANA44 is big enough so
the 5.13 gear will be sufficiently strogn.
But do you think 5.13 can be too weak for the DAN30 axle?
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ARB air pump:
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There are three versions of ARB air pump
Which one do you recommend

ARB Air Compressor for Air Locker (CKSA12) $140
ARB Air Compressor for Air Locker & Tire Inflation (CKMA12) $230
ARB On-Board High Performance 12 Volt Twin Air Compressor (CKMTA12) $495


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ARB locker:
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Front locker (DANA30)
There are choices of 27 spline and 30 spline, which
one should I use?
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Rear locker (DANA44)
There are choices of 30 spline and 35 spline, which
one should I use?
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Air Hose:
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Do I have to use ARB Air Compressor Pump Kit (RDCKA-PK),
or I can just order some air hose from AutoZone?

 

call david at northridge 4x4 he will hook you up with the correct parts

 

This is not an easy decision to make and definately depends on your personal use and expectations. You really want to think this one out and research it so your you do it once and are happy. Definately call Dave at Northridge 4x4 for your parts, he will make sure you have everything you need.

Personally I think 5.13 is way to low for 35s with a 6spd. Unless you are really looking to crawl. I have 4.88s with 37s and performance is the same as stock with 3.73, maybe even a touch better. For a 6spd, I feel 4.88s are perfect for 37s. Now I'm not rock crawling either and my JK is a daily driver

If you plan on taking your Jk on the highway still and want to keep some decent fuel mileage and not have your motor screaming at 70-75, think about going with 4.56s and your 35s. The charts in the modified section of the forum show the 6spd with 3.73s turns about 2300rpms at 70mph. With 35s and 5.13s you will be at approx. 2900rpms at 70mph. If you go 35s with 4.56s you will be just over 2550rpms at 70mph. This will allow you to have a slightly higher rpm to help accomadate the extra heft of your larger tires without having to scream your motor and really sacrafice your fuel mileage.

Now if you are really considering going to 37s. I can tell you from my experience to give the 4.88s a serious look. You won't be dissappointed.

I have Yukon gears from Northridge 4x4. They seem to be very popular and if you look at the threads here. You will find a few that discuss the differences in the manufacturing of the gears. Bottomline for a JK, they are all pretty much made in the same place. The being overseas, most people have not had any trouble with them.
I put overhaul kits in. My feeling is once and done. I only had 20K on mine when I did the swap and still did overhaul kits. You already have everything out, just put in new and be done with it.
Another thing, if you look around you will probaly find that locking a Dana 30 seems to definately increase your chances of breaking it. I found when I was doing mine from talking with others, including manufacturers who are members here, that if you want to run big on a Dana 30 leaving it open will help keep it alive.
That's my opinion, hope it helps. Feel free to PM any questions. Good luck with your choices, just remember to make them based upon your use and need. You will get all sorts of suggestions here, there really is no wrong way to do your build as long as it works for you.

 

Thanks Bonedoc:

Now you made me think about 4.88 again. For your current setup, what MPG do you get?

 

Getting about 17.5-18mpg when cruising. Does drop when I'm reving the motor up around town.

 

I have 6 speed and 4.88 with 35s. Going to 37 with 4.88 probably

 

From your stated needs, 5.13's will be fine, there are plenty of people running them with 6spds and 35's. Rpm's will be a bit under 3k at 70, and power will be great. The strength issue is something that only you can decide on. Base that decision on your intended use. Heavy foot in the rocks, consider dropping down a ratio.

All JK 5.13's are still being imported, compare prices and warranties and get whichever you like. Talk to your installer before ordering, though, as many will prefer that you buy through them and give better prices or better warranties than if you supply. Make sure they are 'JK' gears, which are thicker than non-jk gears.

For low mileage axles, you can get away with install kits, but you are better off with new bearings, so get the overhauls.

The CKMA12 compressor is very popular, as it allows tire inflation. (CKSA12 does not, it is locker only).
The CKMTA12 is brand new and I don't believe many people have it yet. Great flow rate and duty cycle, but it is twice as big, and twice as heavy as the ckma12, so you will have to find someplace to put the thing. (even if it would fit, I would not want that big ass compressor hanging off of my brake cylinder.)

Your stock front D30 shafts are 27 spline. IF you trust that axle enough to lock it, consider upgrading to 30sp shafts and 30sp arb. Also consider C Gussets and Sleeves at the same time. Or just scrap it and get a PR44 or a 60 for the front. (personally, I would not drop a thousand dollar locker into a 30)

Your stock rear D44 shafts are 30 spline. You should be fine with the 30sp arb, but upgrading to the 35sp combo wouldn't hurt.

RDCKA-PK - I don't know if that is a proprietary fitting that will only work on their compressors, but it's worth asking about. Northridge has a good package deal on the compressor with all the add-ons, so check it out, and maybe ask Dave about that fitting.
http://www.northridge4x4.com/proddet...ARB-PKG_JK_AIR

 

"Personally I think 5.13 is way to low for 35s with a 6spd. Unless you are really looking to crawl."


I agree, the 6 speed does not run as much OD as the automatic and 4.88 is a good choice. If you want a little better mileage 4.11's are a good choice. You can use 5th for the hills abd 6th for the flat land.

 

I agree completely

 

Let us know what you decide. I'll be looking at re-gearing as soon as I can save up enough for wheels/tires/lift.