The Ups and Downs of Lift Kits
By Justin Banner
It’s one of the first modifications done on Jeeps and needed if you’re going to run big tires. Lift kits not only can level the height from front to rear, but also give you the clearance you need for off-road obstacles. Though, it does bring up a question: which lift is best for me?
The Purpose of Lift Kits
So, why would you need a lift kit? What is its purpose for existing. As the name boldly implies, it’s designed to lift your Jeep enough so that your tires have clearance between the fenders. There are many ways that can be achieved, and we’ll talk about each one and what tire diameter you should be able to run at each height.
However, the way each lift is achieved gives you different gains. A body lift will give you the height you want without changing anything with the suspension. Coil spacers give you a lift without running a different spring rate. Coilovers will typically give you additional travel with the lift you get. So, you should consider what you’re looking to gain in both lift and in function when it comes to your lift kit.
The first and simplest lift is the Leveling Kit. Generally, it’s a spacer that sits between the top of the spring and its upper perch. While it does nothing for the rear, it does generally raise the front end up one- to two-inches. This generally puts the bottom of the front bumper about level with the middle of the rear, so you do gain some clearance there. Some are made of solid material (like plastic or even metal) but there are others, like the Daystar KJ09152BK, that provides two-inches of lift using a polyurethane spacer. Using polyurethane helps reduce the noise, vibration, and harmonics (NVH) versus a spacer made of harder materials.
The other type of leveling kit that exists replaces the front coil springs instead of adding a spacer. This not only gains you the height but also gains additional travel by providing a spring that is two-inches longer over the OEM Jeep springs. Again, a leveling spacer you gain any additional travel, but in both cases you do have to remove the front springs to install them. Either way, the installation can be done at home with no special tools and you don’t need new shocks to match the lift.
A body lift places several spacers between the frames body mounts and body of the Jeep. This lift gains one-inch to up to three-inches of lift for tire clearance. Much like the coil spacers, these can be made of solid materials to polyurethane. Again, the more solid the material, the more NVH you’ll have to live with. This advantage of this type of lift is that it does not change the suspension, so your ride will remain the same. An excellent example of a polyurethane kit is the Daystar KJ09143BK for the Jeep JK Wrangler, which gives you a 1.75-inch lift suspension lift and as well as a one-inch body lift, but only works with the automatic transmission.
You will have to take shifter linkages and the wiring harnesses into account when you do a body lift. Manual Jeeps can usually only take about one-inch of lift before the stock shifter becomes an issue. You’ll also not gain any additional travel from your suspension. This can be done in your garage, but you’ll need to find a way to lift the body up and hold it in the air as you install your kit. A two-post vehicle lift makes this kind of job much easier but isn’t required.
A coil lift is another simple way to gain height from your 1997 and up Jeep. Well, up to a certain point, anyhow. The simplest kits allow you to retain parts like the shocks, control arms, track bars, and many other parts. These contents of these kits can be as small as the leveling kit mentioned before but can become more and more involved as you lift higher and higher. For example, the Rancho two-inch Sport System (like the RS66119BR5 kit for the JK four-door) comes with a set of new coils and new shocks to match the lift.
By contrast, the Currie Enterprises four-inch lift kit (CE-9807JCE fitting a four-door JK once again) comes with longer control arms, track bar relocation brackets, longer brake lines, and much more. However, you are getting a kit that gives you 11-inches of rear wheel travel and 9.5-inches of front travel. If you’re going that far, then you may want to consider upgrading to a set of shocks like the Fox Racing Shocks 2.0 Performance Series (985-24-011 front, 985-24-012 rear). These will not only match your lift but also give you advantages like more shock fluid, adjustable dampening rate, and something much nicer to look at under the fenders.
For Jeeps built from 1976 to 1995, you don’t use coil overs but that doesn’t mean you can’t get a decent lift. The simplest is replacing the shackles with a set of lift shackles (like the Currie CE-9035A and CE-9034 CJ shackles). These will give you a lift by changing where the leaf spring will rest and can also give you a little more travel out of your leaf springs. Next would be adding a leaf to the leaf spring pack (like the Rancho RS60613, which is for the rear of a YJ only), which will increase the load rating of the leaf springs and, consequently, lift the Jeep. Don’t expect a huge lift out of either of these as you’ll gain anywhere from 0.75- to two-inches (usually if used in combination in the rear).
If you want to start fitting 31-inch tall tires, you’re going to need to get a set of springs that are arched differently. A reached leaf spring will provide more lift without necessarily changing the spring rate in most cases, like the Rancho RS44150 rear and RS44050 front that will give you 2.5-inches of lift. You will need new shocks to match the lift, however. Another radical change is the “flip” the leaf springs with a spring over conversion. In doing this, you’re taking the axle from being over the spring to under it and gaining the diameter of the tube plus the new perch. The downside is that this requires that the spring mounts on the axle be cut off and replaced with new ones that allow the springs to sit on top of the axles. However, you’ll gain 5.5-inches of lift just from using stock arched leaf springs. You’ll gain six or more inches if you use lift springs or shackles with the spring over conversion. The other downside is that your axle will tend to “wrap” under load and potentially cause more wheel hop on hard acceleration and crawling.
Tire Size by Lift and Wrangler Generation
The tire size recommendations will be based off a wheel that is eight-inches wide with a 3.5- to 4.5-inch back spacing, unless noted differently. If you’re looking to fit a set of 31x10.50 tires, you’re going to need at least a 2.5-inch lift which isn’t hard to achieve with a shackle and add-a-leaf or a 2.5-inch lift leaf spring pack. Looking fit a 33-inch tall tire? You’ll need at least four-inches of lift and reached leafs. For 35-inch tall tires, you’ll be better off with a spring-over conversion but you can get leafs re-arched to fit with shackles, though that’s not recommended. Anything taller and you’re in the custom linked suspension territory.
Since the YJ Wrangler is the last of the leaf spring Wranglers, you’re going to follow everything you just read for the CJ. It’s all the same.
These sizes for our TJ example here will be based on a wheel that is eight-inches wide with a 3.75- to a 4.5-inch backspacing. If you are running a different wheel, you’ll have to adjust your measures based off these measurements. TJ Wranglers with a two-inch lift will be able to run up to a 31-inch floatation size tire or a 265/70R16 in LT metric sized tires.
If you want to run a 33x12.50, you’ll need at least a 3.5- to 4.5inch lift. If you want to run 35-inch tall tires, you’ll need 5.5-inch lift, which will mean you’ll need a kit that includes longer arms so that the centers of the wheels stay center of the fenders, too. You’ll also want to get a slip yoke eliminator (SYE) kit and even a constant velocity (CV) driveshaft as well as an aftermarket or modified exhaust due to driveshaft angles. Anything bigger than that and you’re going to be doing some extreme cutting and hammering to fit.
Much like the CJ and YJ, the TJ and LJ are very similar in design. So, much of what you just read for the TJ will also apply to your LJ.
JK Wrangler leveling kits allow you to run up to a 33-inch floatation sized tires or 285/75R17 metric sized tires with the stock wheels with a nine-inch wide wheel with a 3.75 to five-inch backspacing. You can run a set of 35s on most 2.5-inch leveling kits, but that requires you using eight-inch wheels with a 4.5-inch backspacing at most or a nine-inch wheels with a 3.75- to five-inch backspacing. Really, to fit a set of 35-inch tall tires, you need a 3.5-inch lift as that will allow you to have room to let the tires articulate into the fenders with minor trimming.
Fitting a 37-inch tall tire with a nine-inch wide wheel and 3.75- to 4.75-inches of backspacing is not as much of a hassle on the JK as compared to earlier Wranglers. A 4.5-inch lift kit with adjustable arms and minor trimming will allow the tires to articulate into the wells, but you’ll want to consider doing a SYE kit. You could do a 3.5-inch lift on a 37 but it may be a bit close to the fender wells and you’re most likely going to need trimmed fenders or tube fenders. If you want to get something bigger than that or your just want a massive lift, you’re going to have to consider changing over to a four-link system.
The JL is a lot like the JK, but there are enough differences that copy and pasting the things you do for it won’t work. From the factory, the JL already has 33-inch tall tires on the Rubicon models. It can fit a 35-inch tall tire without much fender modification but a two- to 2.5-inch lift would be recommended along with a nine-inch wide wheel with a 4.5- to five-inch backspacing if you want to go crawling. It is possible to fit 37s without a lift and a nine-inch wide wheel with 4.75-inches of backspacing or a stock JL wheel with a 1.75-inch spacer, but you won’t be doing any crawling due to the limited room you have between the tires and fenders. 37s could be fitted with just as little as a two-inch lift, but again a 2.5- to 3.5-inch lift is recommended on a nine-inch wheel with 4.75-inches of backspacing.
Now You Have Your Lift So, you have the first thing you need towards getting bigger tires with your new lift kit. Now, what wheels and tires are you going to fit?