The text on this page is contributed by Ron (Krash80) Pitelka.
ZJ Grand Cherokee 4” Budget Lift...the Front-to-Rear-Swap!
So you want to lift your Grand Cherokee (ZJ) three to 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 speedbump...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 trackbars. The trackbars 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 trackbar 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 trackbars mounted to the frame of the vehicle, but with the axles
completely gone. If the Jeep were sitting on the ground, the trackbar 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 trackbars 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 trackbars cause the axles to “swing” over
to the side where the trackbar 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 trackbar 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 recentering the axles is to purchase
aftermarket adjustable trackbars. Adjustable trackbars can be adjusted to different
lengths to recenter your axles. These are available from JKS, Rubicon Express, Teraflex,
and KevinsJeepParts to name a few. If your ZJ has very high miles, the bushings in the
ends of your stock trackbar might be worn out anyway, so you can look at purchasing
these trackbars as “vehicle maintenance” if it makes you feel better. However, one can
easily spend well over 300$ on just trackbars, and this so-called “budget” lift isn’t quite
so inexpensive anymore.
Well the trackbars need to be longer, and I can’t afford adjustable ones...what else can I
do???
A few things:
-Purchase a rear trackbar bracket that lifts the effective axle mount about 3” so the stock
trackbar geometry is maintained and the axle remains centered. (To my knowledge a front
trackbar bracket is not available through any common manufacturers). Last I recall, a rear
trackbar 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 trackbars by taking the bends out of them in a hydraulic press.
-Cut in half and reweld your trackbars with a spacer and a sleeve to lengthen them.
-Drill new axle mount holes for the trackbars to move the axles over.
-Make your stock trackbars 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 trackbar at home.
*Disclaimer*- Please note though that none of these trackbar lengthening methods should
be attempted unless you are a competent welder/mechanic or this work is done by a
competent welder/mechanic. Trackbars are EXTREMELY important, and your ZJ is
completely undriveable without one. If your home-brew cut-n`-welded trackbar 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 trackbars if you know what you
are doing! If your axles are off center and you can’t afford new adjustable trackbars yet,
it’s not the end of the world; your ZJ will still be driveable, 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 trackbar 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 trackbars 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 autoparts 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 brakelines 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 bumpstops...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 drivetrain...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 bumpstops, or by
extending them a short amount. You do not need those expensive bumpstop extensions
offered by the aftermarket companies; all you need are new slightly longer bumpstop
bolts and few washers to stack above the bumpstops. What you’ll do is remove the stock
bumpstop and bumpstop cup. Then find a metric bolt that is slightly longer than the stock
bolt that holds the bumpstop 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 bumpstop cup just as it came out, but with the
washers stacked above it so it essentially hangs lower than it did before. This extended
bumpstop 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 bumpstops, 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
bumpstops significantly more. It can easily take one inch or more of spacers above the
bumpstop cups to prevent 32” and larger tires from rubbing. In the rear, you can basically
extend the bumpstop 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
bumpstops 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
bumpstop 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 bumpstops.
What about the dreaded DeathWobble I keep hearing about. Will I get that with this lift?
Well to start, let me cover a few things that usually cause deathwobble:
-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 deathwobble?...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 bumpsteer or
deathwobble, 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 deathwobble! If you know that your trackbar or control arms have bad
bushings or that you have worn out balljoints 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 deathwobble 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
deathwobble 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 deathwobble. Is there anything else I can
do???
Sometimes with larger tires, great bumpsteer or deathwobble will be present even
with all new tight front end components, as well as a proper front end alignment. This
deathwobble 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” bumpsteer.
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 deathwobble
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 trackbar 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)-