So, I have a 2008 with a 6sp, 3.21's, and 32's.

I am going to need new tires soon, and will be moving up in size. but most likely to just 33's, maybe 34's. So obviously, I need to regear as 3.21's are horrible as it is.

The correct gearing for 33's is 4.10's. 4.56's at the lowest. As 4.56's with 33's equates to 2730rpm at 70mph. Which is really pushing it.

The problem is.... I CAN'T FIND 4.10 GEARS FOR JK D30! (Easy to find for older HP D30's)

Literally, NOBODY makes them as far as I can tell. I really rather not find used gears from an '07 JK. The only 4.56's I can find are made by USA Alloy, and these gears run pretty loud. I rather have a quality set of gears.

I can find 4.10's and 4.56's for the rear axle, although they cost quite a bit more than 4.88's.


Does anybody know of anybody that makes quality 4.10 gears for the front axle? Or even 4.56's.

Thanks!

 

Call David at Northridge 4x4, he likely has them in stock. I checked my local place online and they had them in stock, so I'm sure David does. They were Motive Gears, and if your gears are making noise it's more likely the install than the manufacturer.

Also, given where you live, in the mountains and elevations of 3,000+ you should think hard about doing the 4.56s.

 

I will give him a call and see. Didn't see them listed on the site.

US Alloy actually says that they are not intended for a quiet running vehicle because they will whine.

Hopefully I can find some. And yeah I live in steep terrain, and my clutch does not like my current gearing. But I do go to the valley and drive on the freeway as well.

 

I have the alloy 4.10's and yes they do whine, however it really isn't that loud, 2 ounces of Lucas diff oil thickened it all up and they're quiet now.

 

Btw, go 35" put in 4.56 and be done with it. ;-) just my opinion.

 

I put 5:13's in my D-30 and I'm running 35's. Best choice I've made.

 

Auto or manual? With a manual that would put you at nearly 3k rpm on the HWY.


msykes: Are you running synthetic oil in your diffs?

 

Looking around last night I found factory replacement d30 4.11's that were used in the 07 x on quadratec. Anyone know if these wouldn't work in a 2012? the cost is a little ridiculous at $385 for just the fronts. Total for just ring and pinion front and rear was around $600. At that price I'm thinking about biting the bullet and getting 4.56's.

 

Those gears would work fine in a '12. And yeah, they are expensive. I suspect because they are no longer being made by Dana-Spicer, so there is a limited quantity.

And yeah 600 for parts is pretty steep. But on the bright side, they would be quality gears.

 

Check out superior gear and axle. They have quality 4:56 gears for the jk.