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Old 10-02-2001, 02:06 PM
Sitting Bull Sitting Bull is offline
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Join Date: Sep 18, 2000
Location: Atlanta, Ga, USA
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INTRODUCTION

A standard (or at least most common) lift technique is to replace the stock leaf springs with new springs that are longer and therefore have an extended arch. By extending the arch, the distance from the frame to the axle increases, causing the frame to ride higher from the road. Increasing this (frame to axle) distance also increases the depth of the fenderwell, allowing for the use of a larger tire adding even more lift.

Most spring companies sell the lifts in two methods, “kits” and “systems”. Kits typically come with new springs for the front, and blocks for the rear. The blocks are simply a metal spacer that sits between the stock rear leaf spring and the axle. Typically, a three inch block is the industry standard maximum, though most places recommend not exceeding two inches. Regardless of what anyone says, never add a block lift to the front springs, and if you ever find a vehicle for sale with front blocks, don’t buy it. If its that messed up, who knows what else is rigged. Our vehicles also exceed the load rating of aluminum blocks, so make sure the ones you get are cast iron or steel. System lifts replace all four springs, and you pay for the difference. This technique is generally recommended, because in SJ’s, the rear factory springs wear out after 15 years or so (draggin’ butt syndrome). Different manufactures sell their systems and/or kits with other equipment as well. In order to do a complete, high quality job, the following will have to be replaced…

All four leaf springs
Shocks
Rubber brake lines (optional, recommended on 3” or more lifts)
Pitman arm (optional, recommended on 3” or more lifts)
A re-alignment will be necessary

Replacing the springs yourself can be dangerous, if you’re not much of a shadetree, it may be worth saving a finger to have someone do it. If you can get a buddy that knows how, or a shop that will let you help, I strongly recommend it. I have replaced the springs on 4 SJ’s now, but I always refer back to the first time I helped a pro.

<<<<Most of the following was written by Mark Wallace, already posted on the tech section of the web page, I added a few new ideas, please let me know any others and I’ll gladly incorporate them>>>>

OK, NOW ON TO THE JOB…

0.) One week before you start the job, start spraying the pivot bolts (at the eyelets of the springs) with a good penetrating fluid. I recommend the product "PB Blaster", spray the bolts twice daily.

1.) Support the truck with the rear tires just touching the ground on solid jack stands.

2.) The first thing that you need to do is get the rear axle off the springs that you are replacing. There are a couple of methods for doing this. For safety reasons I'd suggest replacing the U-bolts at the same time as u-bolts stretch over time. This means that you can destroy the old u-bolts getting them off. Sawzall, torch, cutting wheel, die grinder, etc are all valid ways of getting off old u-bolts. If you don't have these tools than you'll have to do it the old fashioned way, by removing the nuts from the u-bolts. If you can wrestle an impact wrench in there, than do so, if not you'll need a long breaker bar and probably a cheater pipe. The nuts are above the axle (along with the spring) so access isn't great.

3.) With the axle clear of the springs comes the fun part. Dealing with the next six bolts could take the better part of a day, every tool you own, and the better part of your sanity. It's probably easier to start at the shackle end (rear). It's a tension (upside-down) shackle unless someone in the past has flipped it. On the 74-91 frame the pivot is supported on both sides by a box structure, on the earlier frame it is only supported on one side. Take the nut off the bolt on either rear pivot bolt, either the shackle to frame bolt or the shackle to spring bolt. This is a lot harder than it sounds as the bolts can get extremely stuck in worn spring bushings. Ways to get an intact bolt out include, but are not limited to pounding them out with a big hammer or using a pickle fork. On the passenger side there may be a stock exhaust hanger attached to the spring pivot. It can be removed from the exhaust system, at which point it's pretty flexible and you can wrestle it out of the way.

4.) The spring may just drop to the ground or you may have to pry it free. Either way it's really heavy, and it probably wants to hurt you so it's a good idea to clear it's path.

5.) Here comes the fun of the front pivot. On the passenger side it's not that bad because you can get to the nut from the inside. On the driver's side the nut is welded to a piece of spring steel which has an extreme tendency to bend or break. This would not be such a huge deal except for the problem that the gas tank is in the way, and the gas tank is not trivial to remove. Note: this spring steel is not on 79 or earlier models.

6.) Removing the gas tank is for another how-to at a later date, but it's a good idea to know how the gas tank is held on. On the later frame there is a sheet metal skid plate (the one that's always dented) bolted along the driver's side frame rail, and to a couple of brackets up above the rear drive shaft. The gas tank is held to the skid plate with metal straps and as far as I remember the straps do not need to be removed. The drive shaft probably will need to be dropped at least on the differential end. You don't deed to drop the gas tank all the way to the ground to access the bolt.
Note: the area behind the gas tank is a collecting spot for mud and is a breeding ground for rust. Now might me a good time to clean that area up, and paint it.

7.) When I did this job (along with my front springs) I had some of the pivot bolts that absolutely would not move from out of the shackle. If you have a Sawzall (on my want list) you can probably get between the hanger and the bushing and get at it that way, or you can do what I did. I ground the bolt's head off with a die grinder (time consuming) and put a nut on the other side and tightened it until I ran out of thread, at which point I would remove the nut, place some shims on the bolt and go through the whole process over again until I had pulled the bolt through the other side. For the less stubborn bolts a chipping hammer was usually very useful in getting the bolt out, and would give you a usable bolt.

8.) Reassembly is the opposite, but here are a few tips...

The shackle MUST be bolted to the spring before it is installed on the frame. Make sure to mount the pivot bolt with the nut facing outside, or you'll hit the frame under articulation. Put some Anti-Seize on the pivot bolts for future modifications. If you have a later model Grand Wagoneer, there is a track bar that connects the frame to the axle which will need to be removed and cannot be re-used on a lifted vehicle. Bounce the suspension around a bit after your done to make sure you’re not going to kill yourself on the first road test.

9.) After 100 miles, retorque all bolts, due the same at the next oil change and your good to go.

ON TO THE FRONT SPRINGS!!!

1.) Now that you get the general idea, the front springs are essentially the same thing with the exception that the axle is located above the springs. Set up the jack and stands with the front tires just touching the ground, and remove the u-bolts. CAREFUL! IF THE JACKSTANDS ARE NOT SECURE, THE JEEP WILL COME CRASHING TO THE GROUND WHILE YOU ARE UNDER THE FENDERWELL. Make **** sure everything is secure, and I typically have a back-up stand the front crossmember of the frame. Safety really counts when you remove the front u-bolts.

2.) Remove the sway-bar (you don't have to, but you'll be fighting it alot if you don't)

3.) Remove the hinge bolts (what fun) and the springs utilizing whatever techniques or heavy equipment you used on the rear.

4.) Leave the axle right where it's at, and install the new springs. The top of the new springs will be 2-3" (depending on lift) below the axle. Mount the hinge bolts and get the springs in place and tightened down.

5.) Jack the Jeep up until the axle is resting on the springs, then put on the u-bolts, making sure to line up the stud on the leaf spring with the hole in the spring mount on the axle. Tighten it all down and follow the processes discussed earlier. Install the shocks and the sway-bar (if you want it).

5a.) The drop pitman arm is optional, but it is recommended if you are experiencing the Jeep wheel jerking when you hit a pothole or a Honda (this is called bump-steer). The drop pitman arm is self-explanatory, just make sure you get a fork-splitter to remove it. These can be rented at most parts shops.

6) Take'r for a test drive, and be careful with the new handling, you have raised the center of gravity, and the vehicle will roll easier. In other words, if you're doing 65 down a highway, and a pick-up truck in front of you drops a 5 gallon bucket, you'll do less damage nailing the bucket than attempting avasive maneuvers.

[ October 04, 2001: Message edited by: Sitting Bull ]

[ November 06, 2001: Message edited by: Sitting Bull ]
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