I have made the decision to run 35x12.50r16's on my X. Now comes the question that everyone has asked before, but I can't find an exact answer... I am planning on swapping out my gears for 4.88's front and rear, but I am puzzled on what exactly I need to do for this to happen. Quadratec has the Ring and Pinion Sets listed for the D30 front and D44 rear, both at $299.99. I keep reading that it is best to have a D44 up front rather than a D30, and that a person may be able to swap in a rubicon D44 locker and 4.88's front and rear cheaper than simply swapping out the gears. I need some direction to follow for this, I know my electrical like the back of my hand, but when it comes to gearing and axles... I have no clue. My main concerns are:

1. Swapping in 4.88's
2. Is my D30 front strong enough for 35's
3. Would it be cheaper to put a Rubicon locker front and rear w/4.88s
4. Less money the better, but I still want quality

Now after reading some posts on swapping in a Rubicon axle, where is the best place to find these cheap, hopefully brand new not used. Thanks in advance!

 

You are going to get 1 million diff answers on this. I have the same delima but, I live in Utah and have taken my Jk to Moab a couple times and the D30 has no probs holding my Toyo 35s. I have heard keep the d30 in the front and put a selectable locker in while your diffs are apart when regearing. Selectable locker is better than the factory locker that comes in the rubicon D44. The Jk D30 is better than the old style D30 the TJ came with. I'm just telling you what I'm going to do, but others might have diff options.

 

Thanks for the reply, I just don't want to tear the guts out of my D30 while I am waiting to regear it. Hopefully the 35's shouldn't hurt it for a while, I just don't like taking chances. Anyone else?

 

A lot of it comes down to what kind of off-roading do you intend on doing? You can break pretty much anything. The D30 will stand up to a lot of abuse even with 35's. Heck, I ran 35's on my TJ with the stock front and stock rear (D35). People said you shouldn't ride on pavement even with 35's and the D35. I never had a problem. But when riding up hills I also took it easy on the gas pedal.

 

Am I hearing that you believe you can change to a D44 simply by changing the gears, or did I misunderstand?

 

I have had a few brews already, so pardon me for the misunderstanding. If you were going to change out for a D44 axle, you would have to pay for the axle and the gear change on the rear to match. There is no way that you are going to do that for cheaper or even close to the money required to simply change the gears in front and rear.

I happen to be getting my gears changed to 4.88's tomorrow (can't wait). I have D44 and D30 diffs with 35's. I asked the same thing you did of the 4WD shop that's doing my job. He said that the D30 should be fine for 35's. It's when you go to the 37's (or with 5.13 gears) when you start to have problems.

Hope this helps.

 

going to do the same thing as you guys and I have a X too. Still deciding on what tire size though 37 or 35 but I know I am going to get 5:13 superior gears

 

I'm watching this thread too.

 

As mentioned, a lot does depend on what you intend to do with the Jeep. If you're going to be really abusing it off-road on hardcore trails, then you have two ways to go, do it right the first time, or upgrade as you break things. If you're doing moderate off-roading and can take it easy on the gas pedal, it will be more economical to keep the D30 front, re-gear and possibly consider a rear selectable locker. The front Rubicon D44 axles are a pretty good deal though, they seem to run about $1500 from aftermarket suppliers.

I know guys who can't seem to wheel on anything less than D60's without breakage, yet I wheeled my TJ in Colorado, Arizona, and Moab with the D30/D35 combo (stock 30" tires) and never broke anything, but I knew my limits. Many variables to this issue.

 

I have always gone "upgrade as you break" way and it seems like i have saved alot money during past years. First of all it keeps me thinking how i drive, secondly i have noticed i made it without investing too much or overbuilding my rigs.
And all of my breakups have so far been something i can fix on trail or limb back to civilization to have it fixed, but nothing serious. These include things such as torn brake lines (3times) punctured gas tank etc. Not yet anything with power transmission equipment, just got to be even more careful now on.