[Freshmeat]

How terrible of an idea would this be? My 35s are doing great, buuuut... I have 38" SXs on my 79 Bronco that won't be running any time soon. I hate to see them fall apart from dry rotting before I ever wheel on them.

I could get some wheels for the 38s and drag a small trailer with me to the trails, swap to the 38s there, wheel, then swap back before driving home.

I won't be locking the D30 at any point and once things settle out a bit I'd find a Rubi front and regear it and my rear to something a bit lower... and fortify the front axle while I'm at it.

Thoughts? Being unlocked I don't see a whole lot of advantage other than looking beefy. This is more of a "what if" sort of situation that may turn into something if it's somewhat feasible.

 

[PhrogMech46]

Sounds like more trouble than its worth to pull a trailer just for the tires. Think about how much earlier you would have to get to the trail to swap tires so your not holding everyone up. What if the trail isn't a loop? Do you drive back to the trail head to swap the tires again. Speaking of swapping tires I know I wouldnt want to swap 4 tires after a day of wheeling. Oh and what about the spare? Then there is the gearing issue and you failed to mention the lift you are running.

As far as the D30 holding up....I would keep it open, sleeve/truss and gusset it and be easy on the skinny pedal.\

In short I think its a bad idea all around.

 

[Freshmeat]

Swapping the tires wouldn't be a big deal with OBA/Impact (I don't use impact to torque wheels) but on average without air tools it could be done in about 20 minutes.
All of the trails I've ran so far have a primary trail head and they all exit at the trail entrance. We don't have big open expanses where we can wheel through and come out the other end- it's unfortunate, but not a reality down here.
I have a full set of five 35s and a full set of five 38s.
I'm running roughly 3" up front and about 2" in the rear to keep it all level, with Bushwacker flat flares. I've read numerous reports of people doing fine with 37s on this basic set-up and these 38s really measure out to 37.4" or so.

Basically everyone in my "close circle" is saying it's a bad idea, but they're also telling me to do it because they know I probably would, at least to see how it goes. We only live once, but if trying it out for just a couple easy rides could cause expensive problems, I definitely don't want to bother.

I may wait until I do the RK lift before I even try. I'm not sure. At this point, if it wouldn't cause any serious damage keeping it open, I'd "only" be out the cost of the wheels to give it a shot and that would only run me about $200... then I could sell them for at least a few bucks back or keep them for spares on my 35s.

Like I said... I'm just kicking the idea around. I'm not sold on doing this and as long as I plan to keep my Jeep, I definitely don't want to even try it if it'll cause serious issues.

 

[Joneszj]

gussets, maybe a sleeve or truss and run em.

the high pinion dana 30 in the JKs is worlds stronger than people give it credit for.

 

[Freshmeat]

gussets, maybe a sleeve or truss and run em.
the high pinion dana 30 in the JKs is worlds stronger than people give it credit for.

Then there are posts like this. :bounce:
I hear a lot about how strong it is, but I'm still nervous to dive in.

 

[mellowyellow]

i say go for it, ive seen my buddy on a locked d30 run 36 inch iroks no sleeves or gusstes and use plenty of skinny pedal and it held together.

 

[PhrogMech46]

Also consider the bumpstops if they are not set up for the big meats you will have rubbing issues. You will also need to trim the rear pinch seam. Whatever wheels you may decide on getting for those 38's will need proper backspacing. Im not saying that the D30 is the issue, I think that having to swap wheels at the trail head would be short lived.

 

[Freshmeat]

Also consider the bumpstops if they are not set up for the big meats you will have rubbing issues. You will also need to trim the rear pinch seam. Whatever wheels you may decide on getting for those 38's will need proper backspacing. Im not saying that the D30 is the issue, I think that having to swap wheels at the trail head would be short lived.

I wouldn't run them for EVERY trail ride, so swapping wouldn't be a huge ordeal.

As for setting bumpstops, I'm glad you brought that up. It had honestly completely slipped my mind.

I'm pulling both sets of rocker rails this weekend to trim the Rubis a bit better and to fold in that rear pinch seam. At the same time, I may need to go ahead and chop off part of my rear bumper. I'm planning to go with the PSC Brawler Lite, but just dumped a bunch of my Jeep money on server and software stuff for our local message board, so things are tight at this moment.

The 15s I'm running for the 35s have 3.75" backspace. The 38s may fit in that space, but I'd probably order a 3" just to be sure I'm keeping them off my inner fenders and such. If the wheels they're on weren't already at 2" BS I'd probably just get spacers for when I run them, but that would put me at almost zero backspace, so that's not going to happen.

 

[Freshmeat]

Bump.

Any other thoughts/input?

 

[Dancin Dan]

Bump.

Any other thoughts/input?

I thought most JK's had a dana 44 in the rear and a 30 in the front (with the exception of a few in the early production years).

I do know of at least one person who ran 39" tires on the stock 3.21 gears for awhile.

 

[jeepaddons-chris]

I really feel that 35" tires are at the limit of the D30. 37" if you sleeve, gusset and chromo shafts and use some sense. That is with a normal 37" tire. The SX is a heavy brute of a tire. It *will* break the D30. Not bend the tubes (if done as above), not snap the chromo shafts, but your R&P is going to crap all over itself with the shock load, even if not locked if hit the right way.

Now, that said... I had the same idea as you as far as using my aggressive bias swampers on the trails and had some Kelly Safari's that I was going to run on the street. Problem was, it was a PITA and I got lazy and kept the swampers on after trail runs and then all the sudden my nice big lug swampers went bald in a year. If you're diligent about it, it's a great idea having separate street/trail tires though.

 

[oz97tj]

Like above mentioned, what gears are you running? Sure, there are weak parts, but those can all be modded stronger, except for the ring gear. They also get weaker with lower gears.

Also, what sort of trails do you run? This is a big consideration.


FWIW, I have a 30 in my rig. It has 4.88s and an ARB. It's sleaved, gusseted, and trussed. I'm currently running my stock shafts, but will be upgrading sometime in the future. I currently have 35s on it and will likely be doing 37s or 38s real soon. For the trails I run, mostly sandy muddy trails with a few rocks here and there, I'm not worried about it in the least bit. No, it isn't ideal, but I also don't believe it's a timebomb that will break on every outing. I know people that run 37s on locked 30s and beat on them (again, in Michigan so not %100 traction like sandstone out west) and they hold together with occasional axleshaft breaks due to turned wheels, lots of skinny pedal, and stupidity.

 

[azjeepN]

gussets, maybe a sleeve or truss and run em.

the high pinion dana 30 in the JKs is worlds stronger than people give it credit for.

I say DO IT as well! I run 37s on a locked and reinforced D30, for a year now doing blues, blacks and some reds w/ stock axles and trail spares, just in case!! I've said fuck it and wheeled it hard!! I still havent broke it:thankyou:.....Gotta sleeve and gusset it and then have FUN! Good Luck!:koolaid: