Tire size on the D30

[longfiredragon]

Quick question. I read on here somewhere that the biggest tire the front D30 on the Willys can handle is 35s.

And if so, what do you need to do to run 37s? Install different axles?

Thanks

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[AdamG]

Depends what you’re gonna do with it. Axles don’t determine/limit tire size on their own.

 

[longfiredragon]

Depends what you’re gonna do with it. Axles don’t determine/limit tire size on their own.

Thanks.
I am going to drive it daily, be able to do harder trails with a full lift and maybe 37s.

I read the D30 won't support the bigger heavier tires?

I don't know wranglers all that well. This is my first one, still learning. When I refer to axles I am referring to the actual axles inside. Assuming this is correct. Can I / would I need to change out the inside axles to bigger better stronger ones.

Just learning here. Maybe I will do the lift and do 35s, don't know yet.

Thanks for the reply.

 

[kah.mun.rah]

As stated, it all depends on how you drive it. If you don't abuse it, the biggest issue will be your differential gear ratio. Re-gear that and then don't drive it like a race car through the bumps and you will more than likely be ok. We have 250K miles on a JK Sport with 37s and a front D30 and the JL axle is A LOT stronger than a JK axle.

 

[The Last Cowboy]

It's actually a Dana M187, not a D30. It's significantly stronger. You can get RCV axles, lockers, limited slips and trusses for it. If you're going to stay out of the rocks you'll be okay. But, if you were going to spend that much building the axle, might as well get an Ultimate 44 anyway.

 

[longfiredragon]

Thanks.

I do not haul ass on trails. I am as much into taking in the view as having fun on the trail. Plus I am not that experienced yet.

We have done 7 BOH trails and countless fire roads/forest service roads. Some off shoots were pretty bad.

I know from what I have done so far, I would like more ground clearance which would include bigger tires. Not to get crazy but more piece of mind. Of course I do like the look as well.

I would like to do more on the trails. With a 2" spacer lift and 33s I am pretty much forced to do a lot of the bypasses.

It's a ways down the road for me, and from you guys replies I see more research is needed.

Thanks

 

[bllprk]

Please research this topic extensively before you buy anything.

It may be a better / cheaper path forward for you to buy take-off Rubicon axles. You need to have the end goal in mind before you start investing. What do you want the jeep to do? Just look good? Wheel rocks? Wheel sand dunes? Will 37's be enough? This will help you plan out your build.

Rubicon Axles have:
4.10 Gears
Wider
Stronger Axles Shafts
Lockers
Larger Brakes (at least thicker brakes)

You CAN strengthen the axle shafts and the housing on a D30. You cannot strengthen the ring and pinion.

IF you want to Rock Crawl... you will want to get the 4:1 transfer case from a Rubicon as well.

Please consider your fender flares as well. A 3" lift is not enough with the Sport sized fender flares. You would have to get rubicon / aftermarket flares or put in extended bump stops.

That said...

I have a M186 up front and a M220 in the rear. I re-geared to 5.13's and installed a Rubicon transfer case. I run 35's. I have wheeled sand dunes and Moab slick rock with this configuration and nothing has broken yet. I have beat the crap out of it and so far so good.

 

[bllprk]

Here is my build. I purchased a Sport with the intention of being cheap and building it into a wheeler. I go thru the though process behind why one fix led to another fix.

I am very happy with my 35's. I can't do every obstacle, but I can mostly keep up with the big boys. But... I do think that 37's start to open up other issues, that I don't want to tackle.

https://www.jlwranglerforums.com/fo...l-moderate-budget-maximizing-wheeling.107469/

 

[longfiredragon]

Thanks guys. Yes a lot to think about, so much research.

Nice build thread. Fortunately I know I am good for what I do with some of what the Willys came with.

Already has the D44 out back with LSD.

Already came with the bigger brakes front/rear jeep offers.

Already has slightly better gearing in the transfer case.

From the posts here, sounds like I could maybe do a lunchbox locker up front.

A full lift, of my choosing maybe 2" and would probably get 2 1/2 to 2 3/4 on my sport Willys.

The right wheels and 35s.

And my jeep should do everything I need it to for a long time.

Thanks again for all your helpful advise.

Oh, and yes the re-gear.

 

[Zandcwhite]

In my opinion regearing and axle shafts would be the minimum for 37s, but if you're planning on harder trails you'll want a locker too. There's no way I'm investing that kind of money into an axle that's marginal at best for your intended use. I've seen Rubicon axles sell on here for $3500, XR axles closer to $4k. Doing that gets you everything you need for 37s with wider axles for a bit more tire clearance, deep enough gears, better brakes, and front and rear lockers. You can likely sell the Dana 44 with limited slip for close to $1k for someone looking to upgrade their sport. At that point you've spent just the $3k having a pair of axles geared costs and gained lockers and a much stronger front axle in the process.

 

[AdamG]

Lockers aren’t the end-all answer for everybody, consider the kind of offroading (and onroading) you do to drive that decision. If you go the regear route, consider a TrueTrac or Nitro Helix to replace the factory LSD, those clutches can and do wear out. Either of those upgrades will last darn near forever.

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