ZJ Grand Cherokee 4” Budget Lift…the Front-to-Rear-Swap!
So you want to lift your Grand Cherokee (ZJ) three or four inches but don’t want to spend a ridiculous amount of money doing so? The “Front to Rear Swap” is gaining popularity as a great “budget” lift and might be just the lift for you!
Note: This article is a bit lengthy, but should prove to be very valuable to one who desires a high-quality, yet economical lift for their Grand.
What exactly is the “Front to Rear Swap” or “F>R”?
In short, the F>R involves removing your stock front ZJ springs (coils) and reinstalling them in the rear of your vehicle. This provides you with around 3.5-4” of lift in the rear simply because the stock front ZJ springs are about that much longer than the stock rear ZJ springs. Make sense?…I hope so! The front of the vehicle then will get a set of longer aftermarket front springs to provide the appropriate three to four inches of lift to match the rear. Your stock rear springs can then be discarded, stuck on a shelf, or even welded together to become a mailbox post…seriously, don’t even try selling them, you can’t give them away!
The three or four inch front springs that you use can be whatever your budget allows or just whatever you prefer. Common brands of coils used with this lift include, but are not limited to, TeraFlex 3.5”, Rubicon Express 3.5” or 4.5”, Tomken, Skyjacker, Rancho, or ProComp. All of these manufacturers’ springs can provide the necessary lift, however some may require the use of spacers on top of either the front or rear springs to level out the rig accordingly. For example, Rubicon Express 3.5” or TeraFlex 3.5” front coils might provide over 4” of lift to an I6 equipped ZJ with stock bumpers, yet the same coils might only provide 3” of lift to a V8 equipped ZJ with a heavy steel bumper and a winch up front. Also, the stock front springs that you install in the rear can result in different amounts of lift depending on if your vehicle came with an I6 or V8 engine, the mileage on the springs, or if the vehicle was equipped with UpCountry suspension. I’ve found that simply stacking stock “rubber isolators” (rubber spacers that sit atop the springs) on top of the springs is a great way to level out a ZJ. The stock isolators are only about 8-10$ each from your local dealership, and they stack securely on top of one another. Expect about 1/2” of lift difference from each additional isolator. Also note that the front and rear isolators are slightly different in diameter from one another (I’ve found that stock front isolators can be used in the rear, but not vice-versa).
In addition to purchasing new front springs, you will also need new longer shocks all around. Stock shocks are simply way too short for a lift of this height and would bottom-out on a speed bump…so you NEED four new shocks.
Many of the aforementioned spring manufacturers, as well as other companies such as Bilstein, Edelbrock, and Old Man Emu, carry shocks that are the appropriate length for this lift. Check the shock chart found in the “Grand Tech” pages on NAGCA.com for what length shocks work with what height lifts. The ride quality and handling of your ZJ after this lift will also vary greatly depending on what springs and shocks you use. Do your research and find out spring rates and shock dampening qualities before purchasing any parts.
So that’s it? I can simply buy new shocks and two new front springs and maybe a few spacers and be all set with a working four inch lift? That sounds too good to be true!
Well, not exactly…that would be too good to be true. Many other things might be, and usually are, necessary when doing this lift. You will notice after installing a lift of this height that your front axle has shifted slightly toward the driver’s side, and the rear axle has likely shifted a bit toward the passenger side of the vehicle.
“Why is this,” you wonder? This is the result of lifting a solid axled, coil sprung vehicle equipped with front and rear track bars. The track bars center the axles under the body of the vehicle and also provide the lateral stability necessary to keep the axles in place; they are mounted parallel to the axles. The front axle has a track bar that is connected to the frame on the driver’s side and connected to the axle on the passenger side. The rear is the opposite with a passenger side frame mount and a driver’s side axle mount. To better understand why the axles move to the sides as they do when a lift is installed, picture the track bars mounted to the frame of the vehicle, but with the axles completely gone. If the Jeep were sitting on the ground, the track bar would be close to level in orientation and the disconnected (or axle) end would be on the opposite side of where the frame mount is. If you were to magically start lifting the vehicle off the ground, the track bars would swing down in an arc and the disconnected ends would move toward the side where the bar is mounted to the frame. Now, visually reconnect the axles, and you can see how as you lift the vehicle, the track bars cause the axles to “swing” over to the side where the track bar is connected to the frame.
So how do I get my axles back under the center of the vehicle!??
Well, you could just leave the axles shifted over to the sides if they haven’t moved very much; that’s actually what most people who install a 2” budget boost end up doing simply because their axles haven’t shifted all that far. The higher you lift the vehicle, the further over the axle will swing. If you only net 3” of lift from your F>R swap, you might be able to ignore the track bar issue altogether. Most people aren’t that fortunate though, and their axles have shifted a significant amount to the sides. The easiest, and probably best, solution to re-centering the axles is to purchase aftermarket adjustable track bars. Adjustable track bars can be adjusted to different lengths to re-center your axles. These are available from JKS, Rubicon Express, TeraFlex, and KevinsOffroad to name a few. If your ZJ has very high miles, the bushings in the ends of your stock track bar might be worn out anyway, so you can look at purchasing these track bars as “vehicle maintenance” if it makes you feel better. However, one can easily spend well over 300$ on just track bars, and this so-called “budget” lift isn’t quite so inexpensive anymore.
Well the track bars need to be longer, and I can’t afford adjustable ones…what else can I do???
A few things:
-Purchase a rear track bar bracket that lifts the effective axle mount about 3” so the stock track bar geometry is maintained and the axle remains centered. (To my knowledge a front track bar bracket is not available through any common manufacturers). Last I recall, a rear track bar bracket is around 50$ from TeraFlex. This however, in my honest opinion, is not one of the best options though. The lift bracket places a lot of stress on the stock axle bracket, and there have been MANY cases of these brackets causing the stock bracket to rip off the axle during heavy off-roading. If your rig is used 99% of the time on the street though, and your lift is mainly just for looks or to cross a few fields and do some mild off-roading, then this relatively inexpensive bracket may work well for you. But, if you want to keep this a true “budget” lift, then you can instead…
-Lengthen your stock track bars by taking the bends out of them in a hydraulic press.
-Cut in half and re-weld your track bars with a spacer and a sleeve to lengthen them.
-Drill new axle mount holes for the track bars to move the axles over.
-Make your stock track bars adjustable with grade 8 nuts and bolts and some very careful welding. I believe there is also an article on NAGCA.com which describes how to make an adjustable track bar at home.
*Disclaimer*- Please note though that none of these track bar lengthening methods should be attempted unless you are a competent welder/mechanic or this work is done by a competent welder/mechanic. Track bars are EXTREMELY important, and your ZJ is completely undriveable without one. If your home-brew cut-n`-welded track bar were to break on the street, you’d be very lucky to walk away from the accident scene. So PLEASE, only attempt these modifications to your stock track bars if you know what you are doing! If your axles are off center and you can’t afford new adjustable track bars yet, it’s not the end of the world; your ZJ will still be drivable, but may dogleg a bit on the street. Probably the worst result of this will be increased tire wear.
So now I’ve selected my front springs, all my shocks, and decided how I’m going to address the track bar issues. Is there anything else I need to know or do?
Not quite done yet. You will notice that with most any complete three or four
inch lift kit, the manufacturers usually include some control arms. Some lift-kits come with just front lowers, others come with all four lowers, and still others come with all eight lower AND upper replacement control arms. Control arms usually range anywhere from around 50$ each for fixed length ones with rubber bushings on each end, to about 120$ each for articulating adjustable arms with a flex joint on one end, so if you were to replace all eight of them, that would add up REALLY fast! Basically, purchasing new control arms doesn’t exactly go along with piecing together our “budget” lift.
So how do I know if I need new control arms or not?
Every Grand Cherokee is different. Most ZJ’s work perfectly well with all eight stock control arms at four inches of lift. Others, however, might develop undesirable steering characteristics or driveshaft vibrations at only three inches of lift. By installing control arms that have adjustable lengths, you can often change the axle orientation to bring the steering feel close to what it was when stock, or, in the case of trying to stop driveshaft vibrations, you can adjust the pinion angle (angle of the end of the driveshaft as it comes out of the differential) to reduce or eliminate these vibrations. Other people simply replace their lower control arms with aftermarket ones to gain articulation (axle flex / axle droop) off-road. Or, if you’re mechanically inclined and can handle lengthening your track bars on your own, making your own adjustable control arms is not much harder. Whether or not you will need adjustable control arms is determined on a case by case basis.
What about brake lines? I’ve heard I will need longer ones.
If you replace your front lower control arms with aftermarket ones, you will almost definitely need longer front brakes lines. The reason for this is that aftermarket control arms usually allow for greater axle droop than stock control arms, and the limiting factor of your axle droop will become your stock brake lines. Stretching or stressing these lines can lead to tearing or cracking…and that’s bad! Usually the most inexpensive replacement for ZJ front brake lines are stock front YJ brake lines which are supposedly four inches longer than ZJ ones and are available at almost any auto parts stores. Many lift-kit manufacturers carry longer front brake lines for ZJ applications as well. Only the front brake lines will need to be replaced; the rear lines are plenty long for what your axles will do with this lift. If you keep all of your stock control arms, you *can* get away without replacing the front brake lines. They will be just about maxed-out when a front tire is drooped as far as it will go. Some people are not real comfortable with this for obvious reasons, and they opt to replace their front brake lines anyway. Again, it’s up to you and what all fits into your “budget” lift. Regardless of what you use for control arms, the front ABS lines also need to “lengthened” with this lift. But, this is very simple and involves nothing more than sliding one of the rubber grommets that surrounds the ABS line out of its bracket that’s behind the front shock, then zip-tying the ABS line to the shock to keep it out of harm’s way.
Now the BIG question:
WHAT SIZE TIRES CAN I FIT WITH THIS LIFT???
Basically it’s up to you! The easiest and most common tires used with this lift are
31”x10.5” on stock rims. These work well on almost every three or four inch lifted ZJ and will likely create the fewest problems for you. However, if you desire more tire, you can stuff whatever you wish on there. 32”x11.5” tires are tight fit on stock rims, but can be done. Much more care is necessary though to be sure that your axles are perfectly centered to prevent the tires from rubbing on the insides of the fenderwells or the springs. If you must have 32”x11.5” tires, I strongly suggest aftermarket rims with less backspacing (stick out a bit further). You can even fit 33” tires with this lift if you really want to. Again, new rims are strongly suggested, especially if you opt for 12.5” wide tires as opposed to 10.5” wide ones. However, once you get into the 33” and larger tire range, adjustable control arms are almost a necessity, and you might even find that you need to slightly trim body panels such as fenders and bumpers to fit them….or you could add greatly extended bump stops…which I will elaborate on shortly. You could even fit 35” tires on your ZJ with this lift, but you will also have to cut a good portion of your fenders off! Like stated before, 31”x10.5” tires will create the fewest fitment problems for you, give you the closest to stock performance, and produce the least amount of stress on the drive train…I strongly recommend them over larger tires for a daily driver with this lift.
My tires rub and make awful noises when I turn my steering wheel all the way to one side. How do I stop them from rubbing?
This is very common and is nothing to worry about…it’s easy to fix. Many times even with only 31” tires on stock rims, the inside edge of the tire will catch on the front lower control arms during full-lock turns. You can either just not turn your steering wheel quite as far, or you can adjust your steering stops to prevent your tires from hitting the arms when you turn the steering wheel all the way. The steering stops can be found on the steering knuckles; they are small bolts that protrude from the insides of the knuckles and you will see where they hit and prevent the tires from turning any further. Simply remove these small bolts and place one or two appropriately sized washers beneath them before reinstallation to effectively lengthen the steering stops. Then when you turn your steering wheel all the way, the steering stop bolts will hit their stops sooner and prevent your tires from rubbing on the lower control arms. Minimal, if any, differences will be noticed in the vehicle’s turning radius.
Well I solved the problem of my tires rubbing on tight turns, but won’t these bigger tires also rub inside the fenderwells when a tire is stuffed during off-road use?
If you only run 31”x10.5” tires, you can get away with the stock bump stops, or by extending them a short amount. You do not need those expensive bump stop extensions offered by the aftermarket companies; all you need are new slightly longer bump stop bolts and few washers to stack above the bump stops. What you’ll do is remove the stock bump stop and bump stop cup. Then find a metric bolt that is slightly longer than the stock bolt that holds the bump stop cup in place, and find some washers that fit around that bolt. About 1/2” – 3/4” of washers should be plenty of spacer to keep 31” tires from rubbing inside the fenderwells. Simply reinstall the bump stop cup just as it came out, but with the washers stacked above it so it essentially hangs lower than it did before. This extended bump stop will stop the axle before it can go high enough to smash your tires into the fenderwells. The same can be done with the rear bump stops, but I’ve found it’s not even necessary with 31” tires. If you run anything bigger than 31” tires, you’ll probably want to extend the bump stops significantly more. It can easily take one inch or more of spacers above the bump stop cups to prevent 32” and larger tires from rubbing. In the rear, you can basically extend the bump stop bolts with spacers as long as you desire to prevent rubbing, but in the front, I don’t recommend extending them longer than about 1.5”. The front bump stops go down on a slight angle, and if you make them too long, they’ll rub on the front-insides of the springs as the springs compress. If you need more than 1.5” of bump stop extension to keep your tires from rubbing, add a spacer such as a hockey puck to the inside bottom of the spring perch to lessen the distance the axle can move upward before hitting the bump stops.
What about the dreaded Death Wobble I keep hearing about. Will I get that with this lift?
Well to start, let me cover a few things that usually cause death wobble:
-ANY worn out or loose steering or suspension components.
-The front end being out of alignment.
-A worn out steering dampener/stabilizer.
So will you get death wobble?…You might! The first thing that you need to realize is that you are greatly changing the original geometry of the suspension…it was not intended by DC to be used like this, so any great changes like this can lead to strange effects. Our ZJ’s with solid front axles are very sensitive to extreme bump steer or death wobble, but there are quite a few things we can do to prevent against it. As mentioned above, ANY worn out or loose steering or suspension components can lead to death wobble! If you know that your track bar or control arms have bad bushings or that you have worn out ball joints and your front end makes strange popping or clunking noises, get those fixed BEFORE modifying the suspension.
My ZJ only has 20,000 miles on it…all the suspension components are basically brand new…but I STILL got death wobble after my lift!
The first question asked here is, “DID YOU GET AN ALIGNMENT????” A front end alignment should always be performed right after significantly changing the ride height of the vehicle as you are doing with a F>R swap. When the vehicle is lifted, the front axle twists forward and completely changes the caster and the toe settings. A ZJ with improper or out of spec caster or toe settings is far more likely to develop death wobble than one that has been aligned properly. I’ll say it again…GET A PROFESSIONAL ALIGNMENT AFTER INSTALLING YOUR LIFT!
I got my alignment done, but I STILL have death wobble. Is there anything else I can do???
Sometimes with larger tires, great bump steer or death wobble will be present even with all new tight front end components, as well as a proper front end alignment. This death wobble could be the result of a worn out steering dampener. The steering dampener acts like a horizontal shock that basically is supposed to prevent or “dampen” bump steer. If it is worn out, it will act basically like a normal worn out shock will: it will allow excessive bouncing, but in this case, side-to-side bouncing. The Old Man Emu SD40 is currently the most popular steering stabilizer used on ZJ’s. In many cases, this dampener works so well that it may even subdue death wobble even if there are other worn out steering or suspension components. This stabilizer is relatively inexpensive (around 60$) and is probably one of the best items you can add to your front end to make the vehicle feel and act more solid.
So am I FINALLY done then?
You should be close, but even when you complete this lift you won’t be done. It’s a Jeep…it’s NEVER done! We’ve covered what’s absolutely necessary to do this lift, and that’s new front springs and four new shocks, as well as strongly recommended track bar modifications. And we’ve also covered other things that might want to be looked into for personal preference, or things that might be come necessary to resolve problems that develop as a result of the lift. It’s smartest to start with the basic things that you need, and if your system works for you, use it that way! If you come across problems, diagnose them and replace/add parts as necessary to achieve the results you want. There are MANY people now driving ZJ’s with successful F>R swaps. If you take your time and do your research (as you are doing by reading this article), you can approach your suspension lift with confidence and understanding to get the job done correctly and safely.
Good luck, and remember that a lifted vehicle will NOT handle like a stock one. Take
time to get to know your vehicle again and drive it with extra caution.
Keep the rubber side down!
-Ron Pitelka (Krash80)-
I lifted my ‘93 ZJ V8 over a year and a half ago for the first time using the front to rear swap. In the front, I installed a set of TeraFlex 3.5” front ZJ springs with a couple stock rubber isolators on top of them to make up for the weight of my ARB bumper, winch, and V8. For shocks, I used four Old Man Emu ZJ long travels (N39L and N40L). I had my neighbor press out the bends in my rear track bar a bit to lengthen it, and I cut and re-welded, and then sleeved my front track bar to lengthen it to re-center the axles. I kept all 8 stock control arms, brake lines, and bump stops as they were and didn’t have to change a thing. My rig sat at 4” front and rear and was perfect for the 31x10.5” BFG AT’s that I ran. A few months after lifting my ZJ, I got death wobble and couldn’t figure out why, so I added an OME SD40 steering stabilizer and that cured my problems. My total lift cost around 400$ or the shocks and springs, but I could’ve accomplished the same thing for far less had I used different components. I used TeraFlex springs and OME shocks because at the time, they were supposedly the best equipment for my ZJ. I couldn’t have been more happy with my lift. It handled decently on-road, and performed amazingly well off-road. But recently the lift bug bit me again and I desired more from my Jeep so I added long control arms and some taller springs. By lifting it to 6.5”, I created many more problems than I’m prepared to handle right now. So the best advice I can give to someone is to keep their lift as simple as possible. The lift to 4” is a big step…to go up any higher is a HUGE and EXPENSIVE step!
When I bought my ’93 Grand Cherokee, it already had a lift kit on it. It was the not-so-desirable ProComp kit that was advertised as 3″, but gave you more like 2″ after the springs settled. I put spacers in between the coils and the mounts and got an extra 2″ out of the deal, netting around 4″ with stock length control arms. It rode stiff, but still like a “normal” Jeep. Cornering was good, even with the 31″ BFG All Terrain tires, but I was looking for more…something even BETTER off-road. I traded off mostly all on-road drivability when I went to 6″ of lift. I purchased a set of 4.5″ Rubicon Express coil springs and moved my front ProComp coils to the rear, netting 6″ of lift. I had to re-center my axles and needed custom rear and front track bars. I also found out that when I put my 33″ tires on, they rubbed like MAD under flex. So, I fabbed up all eight adjustable custom control arms for the front and rear so that the axles would be centered front to rear in the wheel well. After doing this, I adjusted the front axle caster so that I wouldn’t be wandering all over the road (trying to get the on-center feel you get from a new car). After I did that, the pinion angle was way too much for me to drive and decelerate the Jeep without getting a low groaning vibration that sounded to me like a pinion bearing. I paid a guy $100 and parts of another $75 to have the pinion bearing replaced due to the noise, and of course, that didn’t solve the problem. After a year plus of adjusting it, I am finally problem-free (except for the control arms noises, the tire noise, body roll around corners, rubbing at full stuff, vibrations from pinion angle, horrible bump-steer and really bad on-center feel on the highway). Aside from those small irritating things, the Jeep rides really nice, lol.
(I’m going back to 4″ of lift until I get creative with long arm suspension.) This is the concept that I’d like to leave you with: DO NOT, under ANY circumstances, lift your Grand Cherokee more than 4″ without going to a long-arm configuration. Factory length arms work fine with up to 4″, but start to be REALLY a pain to get everything to line up at 5″ and above!!!! If you have any further questions, do a search on the Grand Cherokee Forum at www.jeepsunlimited.com or at www.nagca.com.