traumawoo

Hi Guys!

So I am about to install the Rock Krawler 2.5 Stock MOD lift and 35" Fierce attitudes. My 2008 JK Sahara (6-speed manual) has
3.21 gears and I want to upgrade to 4.56. Will I need to buy the 4.56 gears only or will there be other items
needed for the re-gearing. I dont have a 4x4 shop close to me to ask these type questions. You guys are always
a big help so I appreciate any info that you all can offer.

Thanks
-dave

Jarodbeg

You'll need the front and rear gear set and with your ride being 4 years old, a master overhaul kit for both front and rear would be recommended also. This includes all bearings and seals for the differential.

Give northridge 4x4 a call. They're a sponsor on here. I got my gear set with master overhaul kits from them for a very good deal!

money546

I'll add another noob question. How long does would the OPs job take? (assuming the install of the above recommended overhaul kit). And, does this type of project require specialized tools? Just curious. Thx!

traumawoo

Thanks for the info! Much appreciated.

Jarodbeg

*Edit: Double post

Jarodbeg

I'd say the time would depend on the expertise of the installer. It could be done by an expert in a matter of a couple hours per axle, whereas it could take a first timer a few days to tackle.

There are some specialized tools (press, torque wrenches, dial indicators, calipers) involved in the job, however I think it could be done without them, just not nearly as efficiently.

I consider myself pretty mechanically inclined, yet I was not ready to take on this type of job by myself. I felt it was worth paying someone who does this on a regular basis to ensure it was done right.

There's a good write up on the internet to give you a better picture of what's all involved. Google "gears by bill billavista"

money546

Thanks for the extra info (and sorry to the OP for the minor hijacking). I'm not sure I'm ready to tackle this either, but ideally I'll find someone who is and will let me assist so I can learn. That's how I've picked up every other skill currently in my bag.

traumawoo

No Worries! Good Questions.

tslewisz

Since you have 3.21's now, you'll need a new carrier for your front D30, whether an OEM open carrier or an aftermarket locker or limited slip diff like a TrueTrac.

wheaties

I just went through your ordeal. The advice above is all good and true. You will have to get the carrier for the D30 front end. Any thing larger than the 3.73 requires the larger carrier. It is also time to think about some extra mods while your mechanic is in there. Especially if you are going as low as the 4.56 you might want to consider beefing up your front axle with sleeves or C-gussets or both. Also your mechanic will be right there to put in a new Detroit True-trac locker in the rear. Since the Dana 44 is pretty common you can probably find a take off (used) one for cheap. And yes hire someone who eats differentials for breakfast and has grease in his tea at night. Just my two cents but when I was regearing I was pretty much set on doing the 4.56:1 ratio as well. But my mechanic convinced me that I would be overdoing it. I have about 4" lift and am running 34ish" nitto grapplers. I went with the 4:1 and I feel like I could go up tire size no problem. Of course if you are planning on building a boulder crawler gear away!!!