separator

4Crawler Offroad
Custom Spring Shackles

Visitor # 66791 since 13.AUG.2001

NOTE: 4Crawler Offroad/MissingLinkZ will be on reduced operations until 07.JUL.2008. New orders may not be processed until that date and e-mail response may be delayed. Stay tuned to this page for updates.

separator

Contents:

[Return to the main For Sale page]

NOTE: 4Crawler Offroad/MissingLinkZ will be on reduced operations until 07.JUL.2008. New orders may not be processed until that date and e-mail response may be delayed. Stay tuned to this page for updates.

Introduction:

Doesn't it seem strange that most places only offer 3" longer spring shackles? For example, stock Toyota spring shackles measure approximately 3.5" center to center. I wanted longer shackles but not 3" longer, so I decided to make my own. The first ones I made involved buying a 3" longer "Rubicon" shackle from Downey Offroad, redrilling one hole in the desired location and cutting off the excess. While this worked fine for shorter shackles, it was somewhat expensive and time consuming.

The Downey Rubicon shackle design uses two, unbraced side plates with straight 18mm through bolts and nylon lock nuts to hold the shackle together. This design allows the side plates to move independently, which reduces stress on the suspension and allows for greater articulation. However, I found the Downey design has one fatal flaw, that is that the bolt tends to remain fixed inside the spring/frame bushing, thereby forcing the shackle side plate to rotate on the bolt. Over time this metal-to-metal contact leads to wear, opening up the hole in the side plate, leading to sloppy handling on the road. But worse yet, the back and forth rotation of the side plate under the nut can cause it to work its way loose, ultimately leading to a loss of the nut (I know, it happened to me) and possibly the entire shackle.

In fact, if you run the Downey Rubicon shackles, be sure to check the tightness of the nuts periodically!

One nice feature of the Rubicon shackle design that I do like is that removal is very easy, since you can pull each bolt out separately. If you've ever struggled with trying to pull out a one-piece shackle out of the frame and the spring at the same time, you can appreciate this advantage.

In light of the above problems, I decided I could make a better shackle, taking the good features of the Rubicon design, and correcting the weaknesses. My first attempt was to tack weld the bolt head to the side plate. It worked for a while, but it made shackle removal difficult as now you could not pull one bolt at a time. So, I ground out the welds and decided to come up with a better solution.

Prototype shackle bolt retainer

I then came up with a retainer (photo above) to hold the bolt (and thus the nut) fixed to the side plate without restricting the inherent flexibility of the design. While this retainer works well it takes a fair amount of time to make and I figured there had to be an even better solution.

Shackle Tabs

My final solution was even simpler, I basically combined the two previous ideas into one. By welding tabs on the shackle to prevent the bolt from turning, yet still allowing it to move independently, I think I've solved all the problems with the original Downey Rubicon shackle design and I've given up none of the benefits. Also, as an unexpected side benefit, the tabs help to protect the head of the lower shackle bolt from damage scraping over rocks. The tabs take most of the abuse and leave the head of the bolt fairly unscathed.

[Return to the top of this page]

Custom Length Spring Shackles:

The shackles use stock size (18mm) hardware to provide the proper fit in the stock Toyota spring and frame bushings. Since the side plates are cut from lengths of 3/8" x 2" steel flat bar, any length shackle from 0" to 3.5" over stock length can be made to suite your needs. Pictured below are some examples of custom 4Crawler spring shackles:

Rear 4Crawler Shackles '89 and later pickup rear shackle 2" over Rear Shackle
(A) 3" longer rear shackle
'84-89 4Runner, '79-'88 Pickup		 (B) 2" longer wide body rear shackle
'89-'95 Pickup		 (C) 2" longer '89-'95 Pickup
w/ stock shackle for reference
Toyota wide body front shackle

Braced front shackle
(D) Wide body unbraced front shackle,
2" over stock length,
3/4" hardware
w/ drilled polyurethane spring bushings		 (E) Wide body braced shackle
3.5" over stock length w/
18mm hardware for stock bushings		 (F) Braced rear shackle
5.5" over stock length
2" longer than stock Tacoma shackle Note the factory offset built into the shackle plates
(G) Tacoma Rear Shackle
'95.5-'04 models		 (H) Tacoma Shackle Installed
Note: The shackles match the factory
offsets on inner and outer plates		 (I) Shackle Spacers to make
your own wide body shackles,
thickness/hole made to order
Greaseable Shackle Bolts .LSPV Bracket .
(J) Greaseable Shackle Bolts (K) Load Sensing Prop Valve
Bracket - For Toyota		 (L)
Spring Shackle Examples

Note that the 2nd generation Pickups ('89-'95) have a shackle hanger that is wider than the spring itself. I offer two options for this, one is a wide body shackle (A) with welded-in-place spacers, or a stepped-down shackle similar to stock (B). You can compare the size of the stock shackle to the longer units. Note, with stock rubber spring bushings, it is necessary to remove the steel sleeve in the spring eye to install the 18mm bolt directly. It is also possible to get the shackles set up with a bolt to fit inside the stock steel spacer if desired.

Also available, custom front shackles. Same basic options as the rear shackles, braced or unbraced, wide body or bent side plates. Also available is custom widths, top and bottom. An example is the Tacoma ('95.5-'04) shackle shown in pictures (G) and (H) above. The factory shackle hanger is not centered directly above the spring for some reason. Instead, the factory shackles have a different offset on the inner and outer shackle plates. By exactly duplicating the factory offsets, the 4Crawler Tacoma shackle ensures that the rear springs are not put under the added stress caused by a symmetrical shackle (as many common shackle designs use) and ensures that the rear axle alignment is preserved.

Also available, custom machined shackle spacers (I) for making your own wide-body shackles. Simplifies shackle fabrication since no bending is required. Common thicknesses are:

Turned from 1.75" OD billet steel, they cam be made with nearly any thickness and center hole size.

And now available are greaseable shackle bolts (J). Bolts are gun-drilled through the head, cross-drilled with a center groove to allow for grease insertion into the bushings or OrbitEye/Johnny Joint type spring end. Then the hole in the head is tapped for 1/4-28 thread low-profile grease zerks. Use of this size thread allows the zerks to be removed and replaced with a short, flat-headed screw to prevent the zerk from being scraped off by a rock on the trail.

For Toyota pickups and 4Runners, a bracket to raise the sensing rod on the axle for the Load Sensing Proportioning Valve (LSPV-BV) is also available (K). BRacket is made to order, it is sized to match the lift.

Also, if looking for shackles to use with non-stock springs, for example, the popular Rancho 44044 springs are 1/4" wider than the stock Toyota springs and therefore cause problems when used with shackles built for the stock width spring. If you can provide the specifications of the spring and hanger setup you are using, 4Crawler Offroad can probably make a shackle to fit your exact needs.

[Return to the top of this page]

Ordering Information:

Hole/ID:

Thickness:

Hole/ID:

Thickness:

Order a set of 4 shackle spacers;

+ $7.00 for US shipping

Order a set of 4 shackle spacers;

+ $12.00 for International shipping

Type:

Size:

Type:

Size:
Order an LSPV bracket for US delivery
$2.50 shipping		 Order an LSPV bracket for International delivery
$12.00 shipping

Note: I've been running various versions of this shackle design for nearly 6 years, including several trips over the Rubicon, Dusy, Fordyce Creek, Santiago Canyon, Moab,the Hammers, etc. and aside from the before-mentioned problems with the shackle plates pivoting on the bolts and backing off the nuts, I've had no other mechanical problems. The 18mm Grade 8.8 bolts are massive (they are only 1/32" under 3/4"), the 3/8" mild steel side plates are massive. Yet, with all this strength, the free side plates allow the shackles to flex for added articulation. The anti-rotation tabs are designed to keep the bolts from turning in the side plates, yet, they still allow the shackle to rack side to side for flexibility.

[Return to the top of this page]

Frequently Asked Question:

At this point, you may have questions about spring shackles:

  1. What are spring shackles for anyway?
  2. Why do I need longer shackles?
  3. How long should a spring shackle be?
  4. How much lift will I get?
  5. What's the difference between the wide body and bent side plate shackles?
  6. Don't other companies make spring shackles?
  7. Do you offer greasable shackle bolts?
  8. What problems might I run into with a shackle lift?
  9. What vehicles do you make shackles for?
  10. What about shackles for other applications?
  11. Braced vs. unbraced, what's the difference?
  12. Are there any drawbacks to using a longer spring shackle?
  13. How long does it take to make a set of shackles?
  14. Lift options: Shackles, blocks, add-a-leaves, or new springs? What is best for me?
  15. 15. Can I re-use my factory shackle hardware with the new shackle side plates?

And here are some answers:

1. What are spring shackles for anyway?
Spring shackles are designed to accommodate the lengthening and shorting of a semi-elliptical leaf spring as it compresses and relaxes. Leaf springs have a built-in arch and when relaxed have a certain eye-eye distance then is somewhat less than the eye-eye distance when they are flattened out. In geometrical terms, this is the chord length vs. the circumferential length of the arc (a.k.a. arc length). So, the shackle is designed to rotate back and forth to make up the difference between the fixed distance from the front to back spring mounting points on the frame and the variable distance between the spring eyes. If you want to get really technical, James Stevenson has an excellent analysis of Shackle Tech
Note that by installing a longer shackle, you'll be transferring a bit more of the vehicle's weight to the axle where the shackle is installed. Its similar to the way the stock car racers "jack" one corner of the car to change the weight distribution. This added weight will tend to cause the leaf spring to flatten a bit more. If the spring was already close to its load limit, you may find you need to beef up the springs a little with an add-a-leaf spring. You can use a commercial kit (be sure to get one with one or more long, thin leaves, not a short, thick leaf) or pick up a set of similar springs at a junkyard and use one or more of those leaves to add to your spring pack.
2. Why do I need longer shackles?
If you assume that the vehicle's engineers/designers spent a lot of time designing the stock shackles to work well with the stock springs, then this makes a good baseline on which to work from.
If you keep the stock springs and only want longer shackles for more lift, see information on that topic below.
When an aftermarket spring manufacturer builds a new spring (usually a lift spring) for a vehicle, there are a couple of basic design strategies that can be used:
1. Keep the stock spring geometry and just use thicker and stiffer leaves to gain lift.
This does give the desired lift but the ride quality is reduced and suspension compliance is reduced.
2. Retain the stock arc-length (see above) but use more free arch to gain lift (an arched leaf will be stiffer than a similar flat leaf).
The advantage of this design is that it will work fine with stock spring shackles.
3. Keep the stock chord length and instead use a longer free-arch which results in a longer arc-length.
For this type of spring, you must use a longer spring shackle or else you may find the stock length shackle will bottom out on the frame and cause excessive stress.
For example I had problem #3 with the NWOR 3.5" lift front springs, but did not with the same maker's rear springs, which used a combination of options #1 and #2 above.
A good rule of thumb is to add 1" of extra shackle length for each extra inch of arc-length. For example, when I installed 47" long rear springs in place of my 45" long front springs, I used a 2" longer (5.5" overall) shackle and it works perfectly. Note this rule of thumb applies if you are retaining the stock spring and shackle hanger locations. If you move those, adjust the shackle length as needed. And you still need a shackle long enough to accomodate the length change in the spring as it flattens.
3. How long should a spring shackle be?
Basic rule is they should be long enough to accommodate the change in length of the spring. Ideally, a shackle should swing from about vertical at full droop to kicked back 30-45° at full compression. A shackle that is longer than necessary won't move as far and can lead to a less supple suspension. I found the following on-line calculator handy for working out shackle lengths:
http://www.saltire.com/applets/triangles/tri3s_executable/tri3s.htm (this link seems to be broken)
Just measure the spacing of the spring mounts, the length of the spring and shackle and work out the angles.
Or see James's Shackle Tech page for the nitty gritty details.
4. How much lift will I get?
Given a spring with the axle located about midway on the leaf, every 2" of extra shackle will equate to 1" extra height at the axle. Usually, you'll get a bit more than that, since the longer shackle won't be kicked back as far. So, for a rule of thumb, figure between 1/2 and 2/3 of the extra shackle length will be seen as lift at the axle. Why is this? Look at the springs, one end is fixed to the frame, the axle is connected to the spring about in the middle and the shackle is connected to the spring at the other end. So every 1" of change at the shackle, make 1/2" of change at the axle and 0" change at the fixed hanger. And since it is frame to axle separation that defines suspension lift, you only see about 1/2 of the additional shackle length in the form of suspension lift. If in doubt, draw a simple sketch of a triangle with the shackle being the short end. Make one version with a short shackle and one with a long one. See how the axle moves away from the frame as the shackle length changes.
As an aside, the following will illustrate some of the pitfalls people make in measuring spring shackles (a compression shackle assumed in the following discussion). So, I was once contacted to make a 7" lift shackle like the person saw on another truck! I replied that this would be a very long shackle (see above) and was the person sure it was 7" of lift? Yes, was the reply, that shackle is 7" long! Ah, I replied, and how is the length being measured? I found out that the shackle side plate length was being measured, from one end to the other. Since the only dimension that matters on a shackle is the center to center distance between the two bolts, one must ignore the ends of the shackle, so assuming 1" overhang on each end, the 7" long shackle is actually only 5" center to center (7-1-1=5). So then is this a 5" lift shackle? No, see above note, so then this is a 2.5" lift shackle, right? Wrong again, lift and length is measured relative to something, you can't have a 0" shackle, see FAQ #1. So what is the shackle length measured relative to? Logically, if you want to describe a lift relative to stock vehicle height, you should also measure the shackle length relative to the stock length. So, assuming a stock Toyota spring shackle in the above discussion (which is ~3.5" center to center) the above shackle is actually 1.5" longer than stock (5-3.5=1.5) or a simply a 1.5" longer shackle. And referring to the beginning of this FAQ answer, we see that a 1.5" longer shackle gives between 3/4" and 1" (1/2 of 1.5"=3/4", 2/3 or 1.5" = 1") of lift. So the point of this rather long discussion was to illustrate how measuring and interpreting the wrong dimensions can make someone believe a 1" lift shackle is a 7" lift shackle!
So, back to the original question, how much lift will I get? Assuming the spring is a simple rigid beam and the axle is locate mid-way along its length, then the above rule of thumb applies, 1" of extra shackle length = 1/2" of lift. However, a number of factors can complicate the issue. First, the axle may not be at the center of the spring. If its located closer to the fixed end, the lift/length ratio is reduced, if closer to the shackle end, it is increased accordingly. Then the spring is not a rigid beam, its a flexible member. So the lift gained will be influenced by the weight distribution on the vehicle (front to rear) and the relative spring rates at both ends. If the longer shackle is placed on a relatively light end of a vehicle or on the end with a relatively stiff spring, you may see more that the simple lift/length ratio of lift, since afterall, the end of the spring attached to the shackle is pushed down the full amount of the added length so in the limit, you may see up to that much lift at that end of the vehicle then proportionately less as you move to the other end. To furth complicate matters, you also need to account for the relative stiffness of the leaf spring in terms of front and rear halves. If the spring is not perfectly symmetric, you'll find that the longer side is softer than the shorter side.
Anyway, given all the above, there is really no 100% accurate way to predict how much lift a given shackle will provide. If you find some place selling "2 in.lift shackles", you should really ask them if they can guarantee that lift. The only thing I will guarantee is that the shackle I make will be so many inches longer than stock, your lift may vary.
So what length shackle should I choose?
Using the above rule of thumb, figure the lift you want will be about 1/2 to 2/3 the additional shackle length. So you'll need to decide that if the lift comes out more or less than you wanted, which way would you "be happy"? That is if you want at most 1.5" lift, then choose a shackle in the 2"-2.5" longer range. If you want at least 1.5" lift, then go for a shackle in the 3" longer range.
5. What's the difference between the wide body and bent side plate shackles?
The basic difference is the wide body shackle maintains the width of the widest bushing and uses two long bolts, while the bent side plate tries to duplicate the stock shackle design and configuration. Wide body shackles work well in the front, where they provide enough clearance to avoid hitting the frame under compression. For applications where clearance is not an issue the bent side plates are fine.
6. Don't other companies make spring shackles?
Sure, many do and often for less money, too. If they have what you need, length and design wise, then by all means get the lower cost shackle. Although do your research, too often inexpensive shackles will use SAE style hardware that won't fit the metric bushings used on standard Toyota leaf springs. If you do get a set of these shackles, I can supply bushings to fit them. Also, if you are looking at an unbraced shackle design, be aware of the problem of having the nuts back off the shackle bolts. Make sure the shackle has a design feature to prevent this from happening.
7. Does 4Crawler Offroad offer greasable shackle bolts?
Yes, greaseable bolts are available, the cost is $7.50/bolt in addition to the cost of the bolt itself (for example, for a set of 4 shackle bolts, parts cost is $25.00, add 4 x $7.50 -or $30 to the cost, for all 4 bolts in greaseable versions). You can also send in your own shackle bolts to have them made "greaseable" if you wish, same $7.50/bolt cost.
The bolts are "gun-drilled" from the head end to the middle, then cross-drilled to allow the grease to exit the bolt. The bolt head is tapped for a 1/4-28 thread zerk. This allows the zerk to be replaced with a 1/4-28 screw for use on the trail. This prevents the common problem of a rock or log scraping the zerk off the shackle bolt.
A couple of things to consider with greaseable bolts:
1. You need to replace stock rubber bushings with polyurethane, since petroleum-based grease will attack rubber. Also note that with stock rubber bushings, grease is really not needed anyway. The carbon black in rubber helps to lubricate the bolt and often rubber bushings have steel sleeves bonded inside and there is thus no sliding contact that needs grease anyway. Simple rule of thumb: poly=grease, rubber=no grease.
2. For maximum effectiveness, the bushings should not have a steel sleeve installed, since the idea of the greaseable bolt is to get grease in between the bolt and the bushing. If a sleeve is present then the grease can't get out of the sleeve.
3. For example, on Toyota bushings, the sleeves have an ID of 14mm and an OD of 18mm and in the poly bushings, the sleeve is easily removeable. So, if you want a greaseable bolt in a normally sleeved bushing, simply order the poly replacement bushing, omit the sleeve when installing it and specify that the bolt for the shackle be made in 18mm instead of the stock 14mm size.
8. What problems might I run into with a shackle lift?
The biggest issue with adding a shackle lift is that you are working with a triangle. One side is the frame, the 2nd side is the spring and the 3rd side is the shackle. The frame stays the same and if the shackle gets longer, the angle of the spring must therefore tilt. The axle is attached to the spring and it therefore tilts and since the differential is attached to the axle, it too tilts, changing the angle of the pinion flange. On typical Toyota spring lengths (i.e.. 48"), you can figure about 1° tilt for each extra inch of shackle, more or less. So, adding a 3" longer shackle can tilt the pinion flange of the differential up 3° in back or down 3° in front. But it is hard to give exact figures, best to measure the angles and then correct the difference. It is hard to give exact formulas or advice here, as adding a longer shackle, while changing the pinion flange angle, also raises the height of the rear pinion (drops the front one), which in turn lessens (increases) the angle of the driveshaft. Depending on the style of driveshaft you are running all these changes may either be good or bad. You may even need to add shims under the springs to correct the angles.
Also, while a longer shackle will give your vehicle some lift, it won't make up for an overloaded leaf spring. That is it won't increase the spring rate, so if the springs were sagging because of too much load, they will still be sagging after installing a longer shackle. The only difference is they will be sagging "higher" than before. Also a longer shackle can allow for more negative arch under compression, unless a taller bump stop is used. As such this can contribute to fatiguing a marginal spring pack faster than normal.
Finally, on many 4x4 vehicles, like Toyota, the rear axle has a "Load Sensing Proportioning Valve" (LSPV) that attaches to the rear axle to sense the ride height and by inference, the load or weight on the rear axle. It uses this "Load Sense" to adjust the front-rear brake pressure "proportioning" to keep the brakes balanced. With a rear axle shackle lift, for each inch of lift, you'll want to adjust the LSPV upward 1" to compensate for the lift. If not done, the LSPV "thinks" there is less load in the rear of the truck and it reduces the rear brake pressure. A relocating bracket is available for Toyota trucks, or you can make your own.
9. What vehicles do you make shackles for?
Currently I have shackles for the following vehicles:
- Front spring shackles for Toyota 4WD pickups and 4Runners, 1979-1985 (and solid axle swap applications)
-Rear spring shackles for Toyota 4WD pickups (1979-1995) and 4Runners 1984-1989
-Rear spring shackles for Toyota Tacoma pickups (1995.5 to 2004 only, 2005 models use a tension shackle)
10. What about shackles for other applications?
If you can provide me the dimensions of the shackles, I can probably make them. What I need to know is the length, center to center on the stock shackle bolts, the diameters of the shackle bolts (i.e. the ID of the bushings in the spring eye and shackle hanger - which may be different than the size of the nut on the end of the bolt) and the inner width of the top and bottom of the stock shackle. See image below for a typical spring shackle and an illustration of the sort of data that is needed. Note I used metric dimensions (since it was am import shackle), but I'm perfectly capable to work with imperial units as well (in fact, its best to use imperial units when measuring domestic shackles):
Typical Shackle Dimensions
And for example, the leaf-sprung Mitsubishi vehicles use the same size and design shackle as Toyota. So, many Mitsubishi Montero, Pajero, or Dodge Raider or D50 pickup would be included (coil-sprung vehicles excluded).
11. Braced vs. unbraced, what's the difference?
Unbraced shacklesBraced Shackles
Pictured above are examples of unbraced and braced shackles. In the braced version, a steel support is welded in between the two side plates to reinforce them. Generally, I find that above 2" longer than stock, braced is a bit more stable on the road. Unbraced has the advantage of increased flex in the springs, since the two side plates can move independently as the spring compress and extend. Your choice, the bracing adds $10 to the cost of the shackles.
12. Are there any drawbacks to using a longer spring shackle?
Changing the spring shackle length will change the angle of the springs and anything attached to them such as the axle. One end of the spring is attached to the frame, the other end is attached to the shackle. A triangle is formed by the leaf spring, the shackle and the section of frame between the front and rear attachment points. Since the spring and frame are fixed in length, changing the shackle length will change the angle between the spring and frame. By how much? It depends on the length of the spring and the length of the shackle. Simple trigonometry will give you the answer, divide the added shackle length by the spring length and take the inverse sine function. For example, on a 48" long spring and a 1" longer shackle, the approx. angle change is 1.2°, a 3" longer shackle on the same spring would make a 3.6° change. What this means is that your pinion angle will also change by the same angle. Whether that is an issue depends on what type of driveshaft setup you have and where the angles are currently. I have a full discussion of the ramifications of pinion angle changes on my Driveshaft-101 page. Information on leaf spring degree shims may be found on my shim page.
13. How long does it take to make a set of shackles?
All shackles are built to order. Typpically allow a week or so for fabrication, depending on order backlog and material availability. Allow a few extra days for greaseable bolts. Once ready to ship, a tracking number for the shipment will be sent via e-mail.
14. Lift options: Shackles, blocks, add-a-leaves, or new springs? What is best for me?
All the above options will provide a suspension lift (blocks assume a spring over axle setup). There are benefits and drawbacks to all the above lift options.
Lift blocks are probably the least expensive lift option (again in a spring over axle setup). However, there can be hidden costs with lift bolts, like a new set of u-bolts. Also lift blocks can also lead to increased axle wrap/wheel hop under hard acceleration. Consider a lift block as a "passive" form of lift. You get the added height but no increase in wheel travel or load capacity on the lifted axle. If you are otherwise happy with the current springs and just need a little more height to level a vehicle, then a block is a good option. Note that "lift blocks" only apply to "spring-over-axle (SOA)" suspensions. That is the spring sits atop the axle and thus a block between the axle and the spring would add to the ride height of the vehicle. In a spring-under-axle setup, a block would actually lower the ride height of the vehicle. If considering a lift block, be sure to factor in the cost of new u-bolts, which may be required, depending on the amount of exposed thread on the existing u-bolts. In a coil spring suspension, the equivalent of a "lift block" would be a coil spring spacer. In a torsion bar suspension, an equivalent of a lift block would be something like a "dropped spindle" or a ball joint spacer.
Spring shackles can provide lift with increase wheel travel to boot, assuming the rest of the suspension will allow that to happen. Downsides are the change in pinion angle that can be corrected with shims. If you are otherwise happy with the current springs and just need a little more height to level a vehicle, then a longer spring shackle is a good option. Spring shackle "lifts" only apply to vehicles with "compression" shackles, that is where the leaf spring pushes up on the spring shackle that in turn pushes up on the frame to support the weight of the vehicle. The other type of spring shackle setup is a tension shackle where spring pulls up on the shackle that in turn pulls up on the frame to support the weight of the vehicle. In a tension shackle setup, a longer shackle actually reduces the vehicle's ride height.
Add-a-leaf springs are a good option to consider if you need to increase the load capacity on a given axle. A good option on the Toyota springs is the Rancho Soft-Ride-AAL kit which has 2 pair of leaves (one long thin pair and one shorter thicker pair) that you can mix-n-match with your existing leaves to make up the ride height and quality you are looking for. With an AAL, avoid kits with just a single pair of short thick leaves, they can damage the existing springs where they rest on the end of the heavy AAL. With an AAL, consider 1"-2" lift about all you will reasonably get. The ride may be a little bit stiffer than before, but if you carry heavy loads frequently, then this is a decent low cost option.
Helper Springs are like the add a leaf spring but often take the form of a coil spring that "helps" the leaf spring carry the oad on it. Some are in the form of air-filled shocks that you can adjust the pressure inside to adjust the "spring rate". Others are air barg that sit between the spring and frame to add lift. Others are like small coil springs installed over the shock absorbers. The final type is a coil spring installed between the leaf springs and the frame; here is a writeup on that option.
Lift springs are of course the best option in terms of performance, but likely the most expensive option as well. There are a wide variety of off-the-shelf lift spring options as well as a wide variety of custom spring mfgs. to consider. With custom springs, best to get your vehicle weighed (each axle separately) and then provide that weight as well as the lift and load requirements to the spring mfg. in order to get exactly what you need.
So which option is best for you? Depends on your needs and your budget. Also, you may find a combination of several lift options may work for you. For example, put on an AAL kit then if you need say an inch more lift, add a 2" longer than stock (~1" lift) shackle on the spring.
15. Can I re-use my factory shackle hardware with the new shackle side plates?
Typically not. Many stock spring shackles are built with thin side plates and the "pins" are pressed or welded into one side plate. The pins are typically not a proper bolt as they lack a hex head and often have a stepped down shoulder and smaller nut on the other end. And since the 4Crawler shackle side plates are made from 3/8" thick steel, the added thickness likely makes the stock hardware too short to fit.

If all this is too confusing, I'd be more than happy to consult with you on your specific application. With a few simple measurements and some basic information, it should be possible to figure out exactly what you need for your application.

[Return to the top of this page]

Installation Instructions:

PLEASE READ all instructions all the way through BEFORE YOU START!
Safety First! Before you undertake any suspension modifications, remember that such mods may change your vehicle's handling characteristics and stability. Raising your vehicle's center of gravity with extended shackles, body lifts, etc., may increase the likelihood of a rollover, especially at high speed or on uneven terrain. Hence, all 4Crawler Offroad products are designed and intended for off-road use only. It is entirely your responsibility to determine the fitness and suitability of this 4Crawler Offroad product for your application. 4Crawler Offroad will accept no responsibility for any unsafe condition, damage or personal injury arising from your use of this product. 4Crawler Offroad products should only be installed by those knowledgeable and experienced with leaf sprung suspensions. Your safety depends on it!

TOOLS NEEDED: You'll need a floor jack, jack stands, wheel chocks, an assortment of wrenches/sockets as need to remove the old and install the new shackles (M18 bolts need a 27mm (1-1/16") wrench), rubber mallet and some good graphite-loaded wheel bearing grease.

  1. Park your vehicle on a hard, flat surface and apply the parking brake. Chock both sides of rear tires if you're working on the front or chock front tires if you're working on the rear. Be sure the vehicle can't roll.
  2. Use floor jack under the axle to lift working end until both tires are 3-to-4 inches off the floor. It is not necessary to remove wheels and tires. Place jack stands under frame rails, close to the spring hangers you'll be working on. Lower vehicle onto jack stands, but leave floor jack under axle. You'll use it to raise and lower axle during shackle installation. Make sure jack stands holds the vehicle securely.
  3. Be sure axle is again supported by floor jack. Un-bolt and remove old shackle bolts and shackles. Slowly release floor jack pressure until tires rest on floor or work surface.
  4. Inspect shackle mounting places, including perches, frame mounts and bushings, for excessive wear or damage. Damaged or worn parts must be replaced with new ones or repaired to as-new condition before the shackles are installed.
  5. Install shackles into upper mounts, probably easiest to install the bolt from the outside, placing the nut on the inside. Apply nuts, but do not tighten all the way yet. The shackle plate with the anti-rotation tabs should ideally be on the same side as the head of the bolt, but it can be placed on the side with the nut if desired.
  6. Use floor jack to raise axle until spring eyes and bushings fit into shackles and insert the bolts. You may want to apply grease to bolts to ease installation and reduce squeaking from poly bushings. Do not grease bolts if using rubber bushings, the petroleum base of the grease will attack and destroy the rubber bushings. You may need to tap bolts with a rubber mallet during installation. Do not force a bolt if it catches or there is excessive resistance. Use floor jack to realign holes correctly. Excessive hammering can ruin bushings and deform shackles.
  7. Tighten nuts. However, do not over tighten nuts until bushings bulge or shackles bend. Over tightening can "freeze" your suspension and prevent it from cycling properly.
  8. Recheck all bolts for proper tightness and inspect periodically for tightness.
  9. For Toyota pickups, 4Runners and Tacomas, the Load Sensing Proportioning Valve (LSPV) sensing arm should be adjusted to compensate for the lift acheived. The sensing rod bolts to the axle and uses ride height to adjust rear brake pressure. If the LSPV bracket was purchased with the shackles, un-bolt the sensing rod from the axle, bolt in the LSPV adjusting bracket with the stock bolts. Then bolt the sensing rod to the top of the bracket with the supplied bolts. Check for proper brake operation and fine tune the sensing rod length/height as needed.
[Return to the top of this page]

(Contact me if interested in more information on any of these items)

And please, Please, PLEASE send me a working, valid e-mail address

I'm now accepting payments via PayPal, and will try to ship in-stock orders within 24-48 hours:

Sign up for PayPal today for FREE

* All prices do not include shipping, which is extra *
[Return to the 4Crawler Offroad page... ]
separator
Questions? --> Send email to me. <-- Comments?
email: sales@4Crawler.com
[Last updated: Tuesday, 17-Jun-2008 13:22:47 PDT]

separator