What is a lift?

In it's most basic term, a lift is any way to get the body of the vehicle away from the ground, usually to fit larger tires. For most Jeeps, up to around 4" lift is pretty simple, and can be done with a moderately-appointed toolchest. Check out the Member's Rigs section of most Jeep-related forums to get an idea of what brands and types of lifts are most popular - and also to find out what to avoid.

For instance, one of the first changes I made to my 1996 XJ was the installation of a Rubicon Express 2" Budget Boost. This meant I made the following changes:

  • Front: The stock coil springs were retained, but a 1.75" poly spacer was added to the top of the spring to push the axle that much farther away from the body.
  • Rear: The leaf springs in the back had an extra leaf with more arch added, along with a longer brakeline. This is commonly called an "add-a-leaf" (AAL) lift and gave me almost 2" of lift back there. I carry a bit of gear with me ordinarily so did not get the full effect of that lift.

When I lifted the same vehicle to 4.5" it became more complicated. Now, I had to replace the following:

  • Front: The stock coil springs and the spacer were removed. New, longer lower control arms, heavier upper control arms, a heavy-duty Trackbar and mount were all added, in addition to exchanging the brakelines for longer ones. I had the option to use swaybar disconnects too, but did not install them at that time.
  • Rear: The stock leaf springs with the AAL were removed. A new, taller leafpack was installed instead, along with a longer spring shackle. That end seemed pretty simple.

Some lifts give you the option of buying an AAL or a full springpack which of course costs more. The downside to the cheaper type of lift is that if your stock springs are already sagged, the AAL isn't always going to provide the advertised lift amount. AALs also increase the springrate (the force required to deflect the spring a certain distance), so they can make a rougher ride. Finally, AALs typically can't be added to a lifted springpack to net the added height - the AAL lift is based on lifting stock springs.

Other lifts may include a choice of a full replacement coil spring, or a spacer. The full coil has advantages because it is a NEW spring at that point, and you're not adding a spacer on top of an already sagged or worn spring.

Here are many of the more common suspension types and the lift methods used:

Blocks: - If the spring pack sits above the axle, a cheap way of adding lift is to remove the u-bolts holding the leaf and axle together. Insert a spacer, typically cast or machined metal or aluminum, and install new, longer u-bolts. This is probably the cheapest method, but disadvantages include the desire to stack blocks; this can lead to loss of the block either through cracking or from u-bolt stretching, sometimes with catastrophic results.
Blocks should never be used on the front suspension if you have leaf springs.
Loose u-bolts can be problematic too since the spacer allows more leverage on the bolts, stretching them.

A few months ago, I even saw someone on eBay trying to pass extruded aluminum tube as a lift block - use solid blocks if they must be used at all.

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This is an overly long shackle on a YJ...the owner finally ditched these in favor of shorter, more stable shackles

These overly-long shackles on a YJ Wrangler were ultimately finally replaced by shorter, more stable ones

A sampling of the shackles available for the XJ.  Credit to NAXJA member EricsXJ for the image.

This image (from NAXJA Member EricsXJ) shows the difference in length between the stock XJ shackle and some of the aftermarket options.

Longer shackles: Since the leaf is fixed to the frame at one end by a bushing, the changing length of the spring as it is loaded/unloaded is taken up by a shackle that pivots and holds one end of the spring away from the frame. By using a longer shackle, the axle is moved farther away from the body, giving lift. This is almost as cheap as a spacer lift, but stability is a concern. Using a shackle 2" longer than normal gives only approximately 1" of lift since you are moving the end of the spring. Longer shackles can wobble side-to-side or even spit bushings out when flexed. Again, this is a bad thing.

In the picture to the left, the RE shackle is approximately 1 13/16" taller than stock, so it gives about 7/8" lift. Likewise, the longer Tera shackle is 3 1/2" longer than stock so provides about 1 3/4" lift.

While not readily visible in that picture, both of the XJ shackles to the left have reinforcement through the center section.

Body Lift: One of the cheapest lift methods around, body lifts are simply spacers that are placed on the body mounts of most Jeeps and pickups. By moving the body farther away from the frame, articulation is not changed yet a larger tire can be fitted. There is no improvement in ground clearance except from ground-to-body since the frame is still at the same height. The engine, radiator, transmission/transfer case, frame and gas tank all stay at the old lower location. This can cause problems with clearance and in the case of the gas filler, so a tall body lift may require a new gas fill line.

Tall (2-3") body lifts begin to put a lot of stress on the body mounts as well so the bolts should be checked for tightness and the mounts checked for cracking. The added work involved with stretching or relocating everything that connects between the body and frame is one reason I recommend other forms of lift, although where needed, a 1" body lift is reasonably acceptable.

  • Uniframe vehicles like XJ Cherokees and the WJ/ZJ Grand Cherokees do not have a separate frame, and cannot be body-lifted
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Rubicon Express 4.5inch coil.  Unloaded length 22 inches Coil Springs: As the name denotes, these springs are shaped in a coil.

Taller coils = more lift.

Coil Spacer: this is commonly included in most "Budget" lifts. In simple terms, the spacer fits over the coil tower and moves the spring away from it's normal mounting surface thereby lifting the vehicle.

This differs from a body lift because the spacer actually moves the suspension, allowing more clearance under the frame. This can also allow for more suspension movement since the wheelwells are effectively 'larger'

This is a 1.75 inch coil spacer going onto the front coil tower of a 96 Cherokee.
This is a 1.75" coil spacer being installed on the tower of a 96 Cherokee

Image pending Add-A-Leaf: this is one of the more common "Budget" lift methods around. As I implied earlier, a new leaf is inserted in the springpack. Most of the time this has a more defined arch than the rest of the springs, and once they are all clamped together this adds lift to the entire pack. Disadvantages include an often stiffer ride. Half-length AALs also seem to add a lot more stress on the existing springs at the end of the AAL. For this reason, I would recommend a full-length AAL if you go that route.

Rearched springs: Some companies will rearch the stock springs to give them "lost" lift. However, since this is still the stock spring, arching more than stock height brings the spring eyes closer together and can cause ride problems. Some will say a rearched spring will lose it's arch rather quickly too, leaving you back where you started. No image

Image Pending New spring packs: This is the best recommendation for a combination of good ride and durability, as the springs haven't been worked and flattened like a 160,000 mile old pack, and are typically longer than normal so the added arch doesn't adversely affect the shackle angle.

Spring-Over Axle (SOA): On some vehicles like CJs and the rear axle of MJs, the spring pack is actually under the axle. Simple math says that if the spring is moved over the axle, you get lift approximating the width of the axle tube+the spring pack height. This varies depending on the axle and springs, but typically around 5-6" is common. There are mechanical factors that need to be addressed including welding new spring perches and determining driveshaft lengths, etc. Using the stock driveshaft after performing an SOA can lead to the driveshaft separating, especially if the pinion angle is low.

There are SOA kits available for many vehicles, and they should address issues like those noted. Especially on CJ and YJ Jeeps, an SOA isn't as simple as slapping a new set of spring perches in place and calling it good. Do some research and if possible, talk to others who have done an SOA before jumping into one on your own.

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created: Apr 19, 2003

Updated November 15, 2005

All content is copyright 2001-2005, and unless otherwise noted content comes solely from the mind and keyboard of Jim "Yucca-Man" Langdon
Any changes or modifications to your vehicle are at your own discretion; I take no responsibility for your lack of responsibility