PAwrangler08

Hello all. Couple questions for everyone, if y'all would be so kind as to help. Little confused in a couple areas.

What I have done: 2008 JKU 3.6L with RK 3.5" X Factor and stock 3.21 gears. Currently running 33s (have been for about 3 years now). Trying to decide what size tires I'm going to get depending on how much it's going to cost me. (Bigger tires more money, even more for gearing). 33s are on Cragar soft 8s with 4.5 BS.

What I would like to do is go up to 35s. From what I am told I will need high gears (numerically). I do my fair share of wheeling, mostly rocks. From discussion with my JKU friends I should go with 4.88 if not 5.13s which is understandable I guess.

Now the confusing part for me (sorry for my ignorance) is what in the hell carriers do it get? I'm not getting lockers this time around, just don't have the funds for it, and the level of wheeling I do, at this point in time it's just not worth it for me. So I've seen on numerous sites open diff carrier case and open diff carrier assembly. Can someone explain the difference for me by any chance? That being said is it true that for the rear D44 I do NOT need to get a different carrier for 4.88 or 5.13 gears, even though I have stock 3.21s? If I get an open diff carrier case, ring and pinion, and master install kit, will that take care of everything needed for the front D30? And if it is true that I don't need a different rear carrier and I get just the ring and pinion and master install kit for the D44 is that cover everything I need?

Last question is about what I've seen advertised on some websites for R&P. I'm a little confused on the difference between D30 and D30 reverse? Would D30 reverse be for a front D30 and D30 be for the rear D30?

Any suggestions are more than welcomed.

Thanks in advance for all the help!

-Blair

nthinuf

Since you have 3.21's and a dana 30 up front, you WILL need to change that carrier. And since you have a d44 in back, you will NOT need to change that carrier.

An open carrier is maybe $80 +/- a bit. Since you are regearing and will be in there anyway, now would be a great time to go ahead and add some traction. (a full case limited or locker would take the place of the open carrier). You can find a d30 truetrac for around $390, which might make more sense than buying another open carrier. And the rear 44 truetrac should be around $460 if you choose to go with one there as well.

And yes, r&p and master install kit for both ends, and an open carrier or full case traction device for the front.

JK's use their own gears, so look for 'JK' D30 and 'JK' D44, not D30/D44. As long as it specifies JK, you have the right gears.


Saw that you have a 6-spd, so edited my advice since I have an auto. I'm sure some manual folks will chime in on gear ratio

PAwrangler08

Ok thanks for clarifying which axles need a carrier. Is there a difference between diff carrier assembly and diff carrier case?

So pay no attention to the D30 reverse? Because I have seen 4.88 reverse rotation R&P that fits "2007-14 JK wrangler, rubicon, and unlimited" and "for D30 front axle"

And you are correct, 6 speed. Sorry I left that out.

nthinuf

The front gears are high pinion reverse cut, but it's a lot easier to just look for 'JK'.

Some of the sites vendors have package deals, and forum discounts. Here is what northridge has on their site:
Package Deals - Gears & Lockers - Drive Train
$500 for d30/d44 gears + install kits
$600 for d30/d44 gears + master kits

They will also have the d30 open carrier in stock (call them and they will set you up with the right one), or traction devices if you choose to go that route.

ZMagic97

You did a 3.6 swap into an 08?

I think 4.56s would do you fine.

PAwrangler08

Hahaha woops. Nope. 3.8L. Apparently can't talk and type at the same time.

planman

With an 08 6 speed and 35s, you will want 4.88s.

5.13s would be great off road, but if you spend much time driving over 60-65 mph, you'll want 4.88s instead of 5.13s.

You can get a Detroit TrueTrac limited slip for less than a full locker. Since the primary cost of a regear is the $800 or so in labor, it might make sense to at least do a good limited slip instead of the open carrier.

PAwrangler08

I was thinking the same as you for gears. But like you said, I travel a decent amount above 60-65 MPH.

Me and my buddy are probably going to be doing the install. He has done gears before. He has his own shop.

nthinuf

A good review before you start.

https://www.jk-forum.com/forums/jk-w...gearing-82262/

Orangeav

I'd agree. I had a 3.8, 37's and 4.88's with a 6 speed. I have since had some changes that included a regear to 4.56 and I've really not noticed a seat-of-the-pants difference. I'd say 4.56 to 4.88's for best overall drivability.