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Discussion Starter #1
I have a kind of silly question...I have a 2008 Jeep Commander 4.7L Sport that i put the 2" spacer kit on and am running 265/70/17 tires on stock wheels and no other modifications. I'm upgrading wheels and to a KO2 tire this year and staying at the same size, but the question my pops and I are arguing about is trail ability...how far can a 2" lift kit take me?

I don't want a rock crawler or anything near it...its my family 4x4 :) But I expect i'll be able to catch on moderate trails etc.? Maybe some small Rock roads or puddle jumps. Is it fully capable or do I definitely have to look into a 4" Superlift?
 

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I am assuming your Commander is Trail-rated - since you have the same model & engine as mine, that would mean you have at least 3.73 gearing in the rear-end. As long as you are not doing any major rock-crawling or deep-water submersions, a 2 inch lift is more than enough for any trail riding & off-roading as long as you know how to drive (off-road).

FYI, I was just checking out the 4 inch superlift yesterday on Superlift's website and it's going to be an expensive upgrade if I decide to do it, the parts alone are over $2,100.00
 

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With the upgraded tires, it will surprise you how far it will go. I promise you'll be able to hang on most of the trails that aren't super crazy. You as the driver will have the biggest impact on the rigs capability. If you don't go crazy and get throttle happy I suspect you'll be astonished at its capability.
 

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Putting a spacer, all it does is raise up the body and force the suspension down in its normal travel. You are just trading rebound distance for jounce distance, there is no gain at all in overall suspension travel. Suspension travel is what gets you the articulation and off-road ability.

Having said that, a 2" lift with spacers does get you more ground clearance which also improves break-over/approach/departure angles and allows you to fit taller tires. Those things will give you an improvement in off-road ability. NOT as much as if you had raised the vehicle "properly" by increasing the suspension travel, but that would also be much more expensive.

Your Jeep was already pretty off-road capable before the bigger tires and lift, so despite going the inexpensive route on the lift, you are going to be pretty off-road capable.

The rear suspension is solid axle, the only thing limiting the rebound is the shocks, so fitting longer shocks will give you more rebound. The spacer may make the coil spring bind at full jounce, if so, and provided your kit was engineered properly, there would be rebound bumpers modifications to prevent damage to the coil spring. If they are needed and NOT there, you can damage your suspension if it rebounds farther than it is capable of with the spacers inserted in it.

This is why replacing springs with taller ones to raise the vehicle is far more capable than just putting in "pucks" or spacers.

The front suspension is Independent Suspension. Independent suspension are limited by how much the control arms and joints can swing/pivot, which is far less than a solid axle that can pivot at any point along its beam. So to ride at higher height, the angles on all the suspension pieces and drive shafts change, increasing the load and wear on those pieces. As well, a longer shock is NOT going to increase suspension travel in most cases, and increasing the suspension travel can get very expensive, usually requiring replacement of the most of the components with redesigned parts altogether.

The 4" lift kits I've seen for the Commander, include new redesigned front suspension pieces, and it is very expensive. Increasing the front suspension by 4" with spacers I don't "think" is practical, the angles on the parts will be too far for them to last, I could be wrong, but I suspect that is why you only see extremely expensive kits that replace front suspension components for 4" of lift.

You see why Jeep Purist bemoan the newer Jeeps other than the Wrangler that have gone with Independent Suspensions instead of long Jeep tradition of solid axles Front and Rear.
 

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Discussion Starter #6
Thanks all...that input is much appreciated as my dad was really pushing me to try to,find money for that 4" lift. No I'm not rock crawling and don't want a huge effect on my factory system which is another reason I went with the 2" spacer. I was just tired of those tiny tires :).

One more question...of I go with an 18" wheel and same size tire (31.6) or a 20" wheel and a 32.5 inch tire I should be good still for trails etc. Right?
 

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NO, shorter sidewalls on a tire equal stiffness and less shock absorption and flexibility. Great for a Corvette doing race like driving on a smooth road, Bad for a Jeep doing off-road driving over irregular surfaces and obstacles.

You want the tire to be able to climb over obstacles (The greater the overall tire Diameter or Height the higher the obstacle it can climb up and over) and the taller the sidewall the more flexible the tire will be (Combine that with lowered tire pressure on the trail) and the tire will flex to absorb shock and allow the tread to flex and better grip the ground.

You don't want to go up in Wheel Diameter while keeping the same overall tire diameter, that can only be done by going to low profile tires (i.e. shorter & stiffer sidewalls).

In fact a few purist Jeepers go around sticking "Mall Rated" badge/decals to Jeeps they see with Corvette like 20" wheels and low profile tires. Most good off-road Jeeps have 15" or 16" wheels with 75% or higher profile tires.

I'd stick with 17" wheels and the OEM 29.5" overall tire diameter at least, if NOT higher like the 31.6" or 32.5" tires.
 

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Discussion Starter #8
thanks....I wanted the fuel vapor wheels but they look so crowded in a 17inch lol. I think I may go with rockstar 2 17inch wheels and stick with my 31.6inch tire. Im afraid I'll run with a 32.5 even with the back spacing of the wheel.
 

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Discussion Starter #9
Just got home on the PC to fully read the threads in more detail...yes I don't/can't really afford the 4" suspension kit at the moment...it's not that i'm not willing to work with the install myself, but that's expensive for minimal gain in my opinion. This isn't a full time 4 wheeler, if I wanted something that i'd put that on i'd stay with a wrangler.

And yes - I CURSE the new BS they call Jeep Grand Cherokees and Cherokees. Independent suspension and air-ride suspension kill this crap. They are trying to find a way to make the wrangler independent and that would kill it so bad.

I just want to take my 7 year old son and me on some cool trails and to some places only a jeep can go while not going through 5 feet of water or over huge boulders lol. I know there's decent trails here in Colorado I just don't want to be fully incapable :).

SO...with that being said, I think my best approach would be to keep with my 2" hockey pucks, a 31.6" tire (unless you think I can fit the 32.5" without rubbing considering the new wheels will have a good back-space) and some decent looking 17" wheels.
 

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There was a rumor the next Wrangler (Model Year 2018) would have independent suspension. The foreign CEO of Chrysler, now FCA, certainly hinted at such. The government safety regs and standards, class action lawsuits, the media, uninformed consumers all push toward going the route of safer, more comfortable ride and handling on highways. People are buying Jeeps in droves just for the image, and never take them off road, so they never know the difference. Even more frustrating are the Jeep owners that complain about their Jeep comparing it to a Honda, as they complain about the ride, handling and need for suspension maintenance, they clearly bought the wrong vehicle, but they think its Jeep's fault their Jeep isn't more like a Honda. The number of Wranglers you see with 22" rims and low profile tires confirm this. Throw in decades of foreign ownership with different priorities, i.e. it doesn't has to be good, it just has to sell attitude; this is where we've ended up.

But, the good news is, enough has been discovered about the replacement Wrangler, it will still be dual solid axle, no independent suspension. So Fiat and its CEO aren't as foolish or shrewd as we thought.

The Bad News, the safety regulators made enough of a fuss, the Wrangler can NOT keep its "Convertible" Exemption for much longer. So, the latest news, Jeep is pre-empting the loss of the "Convertible" Exemption (since that big of a change to the vehicle in between redesigns would bankrupt them) and the next Wrangler will no longer be Open Cab. From what I've read, they are doing something with panels and an open structured integral roof that it will still have a very Open Cab feel to it, but it won't be a true Open Cab anymore.

Back to Hawkeyes questions, your plans sound good. Do a search, there is a thread with max sized wheels and backspacing to make them fit a Commander, that should tell you how big you can go on the tire diameter and NOT get rubbing. There is a pinch-weld mod that you fold over a pinch weld in the wheel well to prevent the rubbing for tires that are close.

Also consider, when you swap out shocks, get Blistien 5100 for the rear, they are 2" longer and thus will provide you more suspension travel on the rear axle. The front can't travel more without expensive mods, so the Blistien 4600 are fine.
 

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Discussion Starter #11
i agree with you Mongo - definitely a lot of street jeeps and i want an inbetween but I grew up in those rough ride jeeps and just love the stiff ride over an air comfort ride. I went with a commander because it wasn't nearly as expensive for me as a Wrangler but i'm eating it reviewing the minimal mods I can do cost comparitively :(.

I've reviewed the threads on tire size, according to them i shouldn't be able to run 265 70 r17 without rubbing but that may be the tire not being overly aggressive.

So here's what i'm looking at, and i've googled and searched and repetitevely done so with no real results.

17x9 5x127 -12mm Helo HE878 wheels with 265/70/17 BFGoodrich T/A KO2 tires. I know those tires will "rub" a little at full turn, however I don't want this wheel bringing them way out past the fender. From my measurements I should get around an inch outside of the fender which isn't much and in my opinion would look great. Can someone confirm for me with a better expertise in the area?

Also - I have a concern when I go off-road officially this year and play a bit, Am I going to "bottom" out or am I risking "bottoming" out on a mildly aggresive trail due to not having a huge amount of room in my fender?
 

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When I was buying rims, somebody suggested I not mount the 265/70/17's on a 9" wide rim. I ended up getting 17x8 Moto Metal 970's.
 

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The tires will come with a min/max/recommended rim width, that it is designed to fit on, or can physically fit on safely.

If the rim width is narrower than the tread, then the tire will have the corners of the tread pulled toward the rim, making a less flat tread portion, i.e. the narrower the rim, the rounder the tire cross-section, the wider the rim the flatter the tread and squarer the tire cross-section.

Its really rare, but in the few cases of a rim width greater than the tread width, that would push the corners of the tread away from the rim, it make tire cross-section shape more trapezoid/triangular.

Recommended rim width for the tire is usually what the manufacturer designed the tire to ride on, and thus would hold the most ideal shape and let the tread make the best contact pattern. Obviously a little off of the recommended rim width will change the shape slightly, often NOT enough to make much of a difference. Perhaps in some cases the vehicle owner might want the tire to perform differently than designed and may choose a different width rim to purposely shape the tire more toward his application.

I'm guessing the max/min rim width are more a safety requirement, maybe a wear/performance and mounting issue as well. At least widest rim, if the rim is too wide, the tire bead can be pulled off the rim during cornering/sideward forces. Narrowest Rim requirement may be more tire wear and performance, I could see way too narrow a rim allowing unsafe things to happen with the tire in out of plane forces, but I think you'd get into uneven tire wear and performance that the manufacturer will NOT warranty against long before a too narrow rim became unsafe.
 

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Also - I have a concern when I go off-road officially this year and play a bit, Am I going to "bottom" out or am I risking "bottoming" out on a mildly aggresive trail due to not having a huge amount of room in my fender?
Bottoming out refers to the suspension, NOT the tires. Too large of an overall diameter wheel can rub, NOT only when turning, but it could rub the fenders before the suspension bottoms out. Of course this kind of rubbing could cause a lot more damage than rubbing inside the wheel well while turning.

The suspension is designed to bottom out without damage, you've modified the suspension which could change how it bottoms out and defeat the bump stops in the OEM design that are there to prevent damage. A good lift kit will be designed to take this into account and have modified bump stops if needed, a few kits don't need them and a few kits do need them and don't come with them. This would cause damage to the suspension if its NOT correct. Tires are only effected if you've put too big of a tire on the vehicle.

You could measure the distance between the suspension and bump stop, then the distance the top of the tire and the point it would contact the fender along the arc of suspension travel. If the distance is greater for the tire to fender you should be good, except the live axle.

Keep in mind for a live axle, what happens on one side also effects the other side, the axle can tilt. So if one side of the axle bottoms out, but the other side goes to max extension, that will raise up the tire on the bottomed out side even more. This is why the Commander and Grand Cherokee have higher fender openings in the rear than the front, giving that raked forward look, even though the floor is level with the ground. Because of a front independent suspension and a rear live axle, the rear fenders need more space above the tires than the front. So, you're going to need more room than just the distance between suspension and bump stop for the rear tires.

The front suspension, I believe the bump stop is a cushion over the shock/strut rod, that hits the body of the shock/strut crush the cushion against the strut mount to prevent damage during the front bottoming out. You bottom out to hard, you will damage the shock/strut.
 
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