RedRubycon

I've recently acquired a new (to me) 2-door 2012 6-speed Rubicon. I got her completely stock, and that's no way to leave a Jeep, so I'm trying to plan out my build. This is my daily driver and weekend wheeler, so I'm trying to keep my build relatively tame to maintain on-road practicality and overall durability while staying on budget. What I need is some advice, based on personal experience (I can look up numbers and charts easily enough, but I'm hoping for some practical real-world information), on where I should go for tire size. I'm pretty well set on getting something wider (and getting new wheels to accommodate that), but I'm not sure if I want to go for the milder up-size of 33's, or the slightly larger 35's. My questions/concerns are as follows:

1) With the 3.6L and 4.10 gears in a manual, will 35's present any particularly grievous reduction in on-road performance? Or is the difference small enough that it won't be hugely noticeable? (I would imagine that the crawl ratio is high enough that it won't make a big difference in low-range work)
2) Will 35's present any significantly increased strain on drive-train components? Obviously bigger tires will equal more strain, but is there any meaningful increase in the possibility of breaking things with 35's on a Rubicon? I can't afford to go around breaking axle components and my steering...

It's also worth noting that when I do get new tires, I plan on swapping to an A/T tire instead of sticking with the M/T's, since they're a little impractical for what I'm doing. I need to keep it usable as a reliable daily driver, and I can't afford major repairs, so if 35's are a little risky I'll just go with 33's. Once I figure out my tire-size goal, then I can start doing some serious shopping for what sort of lift I want to put on it... but that's a discussion for another thread.

Advice and anecdotes are greatly appreciated!

jedg

I'll take a first stab at this, but others will provide some good advise.

1. Drive-train components - regardless of what tire you're going with, I recommend you gusset the Cs on your axle. Don't really put much stake in doing sleeves. From what you describe, I don't see you needing truss.

2. Consider a good set of ball joints (especially with 35s). "Good set' being what you can afford but NOT an OEM set.

3. With a 3.6L, 4.10, and manual, I think you'd be happy with 35s. Folks with this combo will speak up I'm sure.

4. Switching to an A/T... so that's the other piece that will influence #3. Depending on the brand, 35" tire won't be 35"... BFG KO2s run small. (my 37s are really 35.5)

5. As for a wider rim, what width tire are you thinking of running? A 35x12.50x17 tire will fit nicely on the OEM 17" rim and can handle being aired down to 12psi without trouble (from experience)... some folks will take them lower.

Lastly, if you run a 35, you may have to run spacers and look at trimming (or like you said purchase a new rim with proper backspacing). I know that you can run 33s without trimming and no spacers. (wife runs 33s on OEM rims without trouble).

RedRubycon

Well, my plan is is go either 35 (or 33) /12.50/15. I could stick with the stock rims, but the backspacing on the stock rims is a lot higher than I'd like. I want to avoid rubbing anything, even at full flex/lock, so getting the wheels to stick out a bit will help, plus add some stability. I'll be getting a lift, likely around the same time as the new wheels/tires, just not sure exactly what yet. Something either 2.5" or 3" most likely.

resharp001

agree 100% with jedg up above. regardless of 33 or 35 you really need to plan on ball joints if you're gonna be wheelin. slap some gussets on cuz those C's are flimsy. 4.10 gears and 35's are gonna be just fine. That's kinda the tipping point though....and you're right, in 4lo it's not going to matter with a 4:1 TC. Odds are if you go 33s, you'll soon just wish you went 35 instead.

Last thing....don't get in your mind that a lifted jeep on larger tires can't be a tame daily driver. You just have to make sure to do things right. Do not accept a crap ride and chalk it up to "oh, it's a lifted jeep". The biggest problem is "right" is seldom cheap.

RedRubycon

Hah, yeah, exactly resharp: It's mostly a matter of doing it "right" without breaking the bank. "Tame" isn't really a concern with the daily driver thing, it's more that I want to keep modifications on the lower end for A) cost reasons, and B) so that I didn't waste my time getting a Rubicon. If I was going to go crazy enough with mods to require a new transfer case, axles, etc. I would have been better off getting a Sport. But since I have a Rubicon, I want to try to keep as much of that factory goodness as I can.

jedg

So knowing you're leaning toward 15 rims, be sure you research if they clear your rotors.... some won't.

RedRubycon

Yup, that's the other thing I'm working on. I've found plenty of lists of rims "guaranteed" to clear the brakes, but most of the lists are older and the specific make/model of rims aren't available anymore. It's proving to be a bit of a headache, in fact... Don't want anything fancy (in fact, the less fancy the better), just a 15x8 alloy rim (preferably black) that's on the cheap end.

tjkamp

I'm running a 2-door 2013 Rubicon Manual with 4.10s and 315/70R17 (35in Metric equivalent) Good Year MTR Ks. There are a ton of things to think about when upgrading the Jeep. If you are going with 2.5-3in of lift you will be able to clear 35s so why not go for it? Depending on where you live and how you drive the 4.10s and 35s can be pretty good. I live near the Texas coast, and I wheel in the rocks a few times a year, I wouldn't mind changing up to 4.88s, but that most likely will never happen, and that's ok. The factory gears work for me (I can still start in second, although with the factory 32s I could start in 4th).

When looking into lifts the main thing to think about beside completeness is weight. Are you going to be adding steel bumpers and a winch and all that fun? Some kits give more lift than others, if you are going to get heavy, maybe look at heavy lift springs offered by some companies, or opt for springs designed for 4-doors rather than 2-doors. (I am getting ready to change my springs because my 2.5in 2 door Teraflex springs are currently only netting me 1.5in of lift in the front, and the back is way worse)!

My Jeep is fairly heavy, for a 2-door, on the local sheriff's commercial vehicle scales she comes in a 4,750lbs, empty with no one in it, and only 1/4 tank of gas.

I have replaced my drag link, tie-rod, track bar, and front lower control arms. I don't get to play in the rocks very often, but when I do we tend to get pretty serious. As long as you go easy on the skinny pedal, you don't have to worry too much about breakage, I'm still on the stock ball joints with 113,xxx miles. I do not have any axle improvements, and as of yet haven't seen the need to. (I'll probably snap something the next time I go out). If you do decide to do C-gussets, you will have to replace the BJs right away, the factory ones have plastic, and cannot take the heat, they will be shot almost immediately after the gussets are installed (not from personal experience, just from everyone I know that has them).

Keep in mind, that while some 15in wheels are "guaranteed" to clear the stock brakes and steering components, they likely will not clear aftermarket steering and brake components. Steering being the big one here. Many aftermarket replacement components require a 17in wheel, synergy included. At some point you will have to replace steering components if you wheel (the stock components are garbage and ware out much faster than you would expect). You aren't going to want to replace them with more stock components when the aftermarket isn't that much more expensive and is way stronger. You just don't want to make it so that you have to buy new wheels and tires because it is time to replace your drag link and tie rod. All of the brake upgrade kits require a 17in wheel.

Also, the choices for different kinds of tires is much more open with 17s than 15s.

Happy Jeeping! Enjoy the new ride! Get out there and see what you really need, they are pretty sick in stock form. If you are rock crawling you will want 35s, if you are just bouncing around on forest service roads, the 32s/33s are plenty good!

RedRubycon

Awesome info, thanks TJKamp! I've already got steel bumpers, winch will be incoming sometime in the next couple weeks... It's heavier than stock, but hard to say by how much exactly, at least for now. It's going to be gaining a bit more weight over time, though I am trying to keep things as light as I can... Now I'm starting to wish I had jumped on a gnarly 8-arm lift I saw on craigslist for a 4 door. Ah well, such is life, I suppose...

The bit about aftermarket steering upgrades requiring larger wheels isn't something I had thought about... I'll do a bit more shopping around and see what I can find, since budget is really one of the biggest concerns when going with one setup vs. another.

Now to go post a "what lift!??" thread and try to start doing some more research on that end of the equation...