Bolt-On Four-Link By Chassis Tech

Anyone with a radically lowered sport truck suspension -- meaning anything typically below a 6/8-inch dropped stance -- understands what it means to either high-center the truck's frame, or better yet, severely bottom out the truck. These are just ways of life with the down-'n'-dirty crowd. However, there are alternatives. The aforementioned problems are a key reason why adjustable suspensions have become so popular these days and are quickly gaining a reputation as the items to have whenever contemplating a new ground-pounding suspension stance. One of the earliest pioneers of completely adjustable air sprung suspension systems has been Chassis Tech, sold through AIM Industries in Phoenix, as well as numerous other authorized Chassis Tech dealers.

Just as the typical lowered truck suspension has changed over time, from simple heated or cut coil springs to lowering blocks to properly equipped frame saddles and dropped spindles, Chassis Tech has also experienced a rebirth of its air suspension pieces. While the typical double-convoluted air spring and less air-efficient air compressors are still popular with the low-end crowd, shopping for the best prices, times, and pocketbooks have changed. While we are not advocating running out and purchasing the most expensive airbag suspension kit on the market, there are idealists out there who believe you certainly get what you pay for. Face it, the suspension on your truck or SUV is your vehicle's last line of defense should something seriously happen to the bottom of the truck, such as blowing out a tire or collapsing an airbag.

While Chassis Tech offers entry-level-type kits, it also specializes in air suspension systems to make the most sheepish person take notice. One key advantage of air suspension systems stems from the fact that at the touch of a button, usually mounted within reach of the driver, the truck or SUV can be radically raised or severely hammered to achieve just the look you desire. A history of adjustable suspensions is something not altogether new. In the late '50s and early '60s, adjustable suspensions became popular with the lowrider crowd through the use of hydraulic liftgate cylinders, which were retrofitted to a car's suspension and typically installed in place of the stock shock absorber. However, one of the main reasons the lowered suspension industry came up with air suspension is the numerous problems associated with hydraulics. Typically, a hydraulic suspension uses a series of hydraulic pumps, holding the oil in reserve tanks for use when the paddles, buttons, or levers are flipped to alter the vehicle's ride height. The downside of hydraulics are the harsh, punishing ride qualities, the difficulty in proper frontend alignment, and, worse yet, blowing out hydraulic pumps.

These reasons alone were plenty for AIM Industries and Chassis Tech to offer air springs and suspensions for the common man to the most prudent of suspension specialists. Knowing Chassis Tech's reputation for high-quality bolt-in parts, we elected to use the company's exclusive new Blow Jax adjustable air suspension, consisting of front control arms and air springs, as well as the company's brand-new air-adjustable rear four-link kit. The entire system comes with race-bred technology and heavy-duty adjustable Heim joints. It is perfect for our latest SEMA project vehicle. We provided a brief sneak peek of the brand-new 2001 Ford Super Crew project in past editorials and a small photo of the completed truck in last month's SEMA Show coverage. This lead photo was computerized to show what can be done. The actual truck will be seen at a later date.

Our reasons for choosing the Chassis Tech air suspension system were easy. First, we wanted to showcase the unlimited possibilities for true bolt-in suspension products, especially one as radical as a rear four-link. Secondly, we wanted to highlight the quality of what it takes to properly set up a decent air suspension system. With that in mind, we called AIM Industries. After explaining to them what we wanted and our short window of opportunity to get the Super Crew to the SEMA Show, a complete kit was sent out. It included all necessary mounting hardware, the air lines, the compressors, the fittings, the airbags, and the rear four-link kit that, to our surprise, was chrome-plated to highlight the suspension's qualities. Follow along as we take you through an involved, proper way to install an airbag suspension system from Chassis Tech.

Sources

AIM Industries
Dept. TR
260 S. Hibbert
Mesa, AZ 85201
(800) 842-8789
(480) 668-5448
www.aimind.com
www.truckin.com

Chassis Tech
Dept. TR
234 S. Hibbert
Mesa, AZ 85201
(480) 898-9049
www.chassistech.com

L&G Ent.
Dept. TR
882 W. Cienega Ave.
San Dimas, CA 91773
(909) 599-2203

Take note of the ground-pounding suspension stance of the world's first airbagged Ford Super Crew fit with a completely adjustable air suspension.
Take note of the ground-pounding suspension stance of the world's first airbagged Ford Sup
The frontend Chassis Tech Blow Jax air suspension kit consists of a new 1-1/2-inch-diameter, 0.188 wall DOM tubing hollow wall upper and lower control arms. Fit with a 2,600-pound air bellow, the frontend can be raised or lowered 6 inches at the touch of a button. However, what does make the upper control arms slightly more exotic is the adjustable and greaseable 6-degree (plus or minus) camber/caster angle. After the Chassis Tech suspension is installed, the adjustable camber/caster angle will make aligning the frontend much easier.
The frontend Chassis Tech Blow Jax air suspension kit consists of a new 1-1/2-inch-diamete

Out back, the Blow Jax 1-1/4-inch O.D. tube four-bars are also adjustable by as much as 6 inches to allow the user to tailor the rearend any way desired. With the adjustments completely tightened, for our application, they came 24 inches in length. Each rod end or Heim joint is completely greaseable, thanks to fitted zerk fittings. Also pictured is the chrome-plated Panhard rod. This is the only piece that needs to be welded to the rear frame and axle at both ends. Without the new Panhard rod, the rear axle will not be centered in the wheelwells.
Out back, the Blow Jax 1-1/4-inch O.D. tube four-bars are also adjustable by as much as 6
Pictured is the massive 1-inch Heim joints fit to each end of our four-link bars. Being adjustable also allows the truck user to tailor the four-link to their needs. For example, the truck used for drag racing can have the rearend pinion angle set more downward for better launching, while the show guy can simply set the angle even with the front. It is this flexibility that makes the Chassis Tech adjustable suspension kit so unique.
Pictured is the massive 1-inch Heim joints fit to each end of our four-link bars. Being ad

Included in the Blow Jax rear kit are the necessary mounting plates. These 0.250-inch-thick plates act as the front and rear four-bar attachments and will eventually bolt on in place of the stock front leaf spring hanger. The rear saddles simply cradle the axle and are fit with the double-bellowed airbags.
Included in the Blow Jax rear kit are the necessary mounting plates. These 0.250-inch-thic
No rear Chassis Tech air suspension is complete without a frame C-notch and section plate saddles. The Super C-notch allows the truck suspension to hang roughly 7 inches closer to earth when properly installed. Fit to the top of the Super C-notch is an additional steel plate, which helps further reinforce the truck's original frame, especially when this drastic of a cut was made to the metal.
No rear Chassis Tech air suspension is complete without a frame C-notch and section plate

The most unique feature of the Chassis Tech adjustable air suspension is the four air valves that flow 75 cfm (cubic feet per minute) and not more than 150 psi (pounds per square inch). Each 1/2-inch air valve will allow back-and-forth movement to adjust the air suspension from front to rear and side to side. Each valve will be controlled by a separate air gauge, so we will know exactly how much air resides in each side at any given moment. The 30-position switch panel is what allows us to make the truck literally dance on air.
The most unique feature of the Chassis Tech adjustable air suspension is the four air valv
Storing all of our necessary air to make the truck dance is this 9-gallon air tank fit with dual 1.5hp air compressors, flowing 165 psi and 8 cubic feet of air per minute. Also attached to the top of the air tank are 100 percent duty cycle circuit breakers that will withstand extreme heat and bone-chilling temperatures.
Storing all of our necessary air to make the truck dance is this 9-gallon air tank fit wit

Another look was needed to check out the heart of the Chassis Tech air suspension system. We affectionately dubbed the kit a V-twin compressor system because of its semblance to the venerable Harley-Davidson motor.
Another look was needed to check out the heart of the Chassis Tech air suspension system.
For additional air storage capacity, we also installed an additional 5-gallon air tank that was mounted up and under the truck's bed. This additional air tank will further reduce the wear and tear on the V-twin. In actuality, you probably wouldn't need the tank, but we are firm believers in overkill, and this system is definitely top-notch.
For additional air storage capacity, we also installed an additional 5-gallon air tank tha

Prior to installing the new front Chassis Tech adjustable air suspension, the stock front upper and lower control arms, the spindles, the springs, and the endlinks were removed. If you have any doubts as to how all of these components need to be removed, purchase a chassis manual and follow along. Upon removal of all of the stock front suspension, the new Blow Jax lower control arm was reinstalled into the stock location. Take note of the greaseable zerk fittings.
Prior to installing the new front Chassis Tech adjustable air suspension, the stock front
Before installing the air bellow, the included upper airbag attachment needed to be fit to the top of the bag. Hardened steel hardware is included in all Chassis Tech suspension kits. Tighten these nuts down to 30 lb-ft of torque.
Before installing the air bellow, the included upper airbag attachment needed to be fit to

At the same time, the Blow Jax lower control arm was fit with the new 1/2-inch air lines. At some point, all four of the air lines running to each airbag will need to be tucked up and hidden inside the frame to keep from being damaged by potential road hazards.
At the same time, the Blow Jax lower control arm was fit with the new 1/2-inch air lines.
The top of the airbag could now be fit with the in-line 1/2-inch NPT fittings. Also attached to the air fittings is the 1/2-inch heavy-duty DOT air line.
The top of the airbag could now be fit with the in-line 1/2-inch NPT fittings. Also attach

Since there is no air in the bellows, compressing them to fit onto the lower control arm shouldn't be a problem. Tighten the new airbag and saddle plate to 30 lb-ft of torque.
Since there is no air in the bellows, compressing them to fit onto the lower control arm s
The upper mount simply attaches in the upper shock absorber mount. Tighten the nut down to 45 lb-ft of torque. This is what makes the Chassis Tech air suspension system unique; it truly is a bolt-on affair.
The upper mount simply attaches in the upper shock absorber mount. Tighten the nut down to

In addition to the new, adjustable upper control arms with the degrees of camber/caster angles, Chassis Tech also includes new heavy-duty ball joints as well as the proper 3/8-inch mounting hardware, which needs to be secured to 30 lb-ft of torque.
In addition to the new, adjustable upper control arms with the degrees of camber/caster an
In addition to the adjustable camber/caster angles on the upper control arms, Chassis Tech also provides knockout plates on the upper arms pivot points. These allow the alignment specialist easier access to set toe-in, toe-out, and the proper camber and caster angles.
In addition to the adjustable camber/caster angles on the upper control arms, Chassis Tech

Lift the lower control arm and compress the airbag so the stock spindle can be worked into position. Fit the spindle to the lower ball joint and tighten the ball joint nut to 60 lb-ft of torque. Repeat the procedure on the upper ball joint. Also, remember to install new cotter pins to ensure the spindle nuts will not loosen up.
Lift the lower control arm and compress the airbag so the stock spindle can be worked into
The best way to gain access to the rear suspension to install the Chassis Tech four-link is to remove the truck's bed. Four large bolts are all that hold the bed floor to the rear frame. Also, the gas filler tube and the bed ground strap will have to be unbolted or removed.
The best way to gain access to the rear suspension to install the Chassis Tech four-link i

After the rearend has been properly supported, the stock leaf springs can be unbolted and removed. The front and rear leaf spring hangers will also need removal. The easiest way to remove the heavy-duty rivets is to cut the heads off and knock them out backward or use a step drill bit to slowly drill out the massive rivets. Upon removal of the stock hangers, fit the new Chassis Tech front four-bar hookup to the truck's frame.
After the rearend has been properly supported, the stock leaf springs can be unbolted and
Using the supplied Grade 8 mounting hardware, fit the new spring hanger to the truck's frame and install the bolts, tightening them down to 45 lb-ft of torque.
Using the supplied Grade 8 mounting hardware, fit the new spring hanger to the truck's fra

The upper axle four-bar plate is next on the list of items to be installed. It needs to be positioned parallel to the front spring hanger and will be attached to the truck's rearend with heavy-duty U-bolts.
The upper axle four-bar plate is next on the list of items to be installed. It needs to be
Fit the lower air spring perch to the bottom of the truck's rearend. The axle saddle fits snugly to the rearend, and the U-bolts can then be mounted around the axle and the Chassis Tech spring perches. Tighten the supplied hardware to 60 lb-ft of torque.
Fit the lower air spring perch to the bottom of the truck's rearend. The axle saddle fits

Measuring the four-bars, we determined that each needs to be set at 24 inches. These can be adjusted to fit each individual's rearend. It is always a good idea to take the proper time to make measurements precise so you do not end up having to redo what has already been accomplished.
Measuring the four-bars, we determined that each needs to be set at 24 inches. These can b
Attach each four-bar into the front Chassis Tech spring hanger. With the supplied 5/8-inch bolts, these should be tightened to 60 lb-ft of torque.
Attach each four-bar into the front Chassis Tech spring hanger. With the supplied 5/8-inch

Secure the back of the four-bars to the already installed rear Chassis Tech airbag bracketry. Again, tighten the 5/8-inch hardware to 60 lb-ft of torque.
Secure the back of the four-bars to the already installed rear Chassis Tech airbag bracket
The upper airbag mount must also be installed. Using the supplied paper template for the bracket's precise placement, carefully drill into the truck's frame so the holes can be applied and the bracket installed. Secure the mounting hardware to 30 lb-ft of torque.
The upper airbag mount must also be installed. Using the supplied paper template for the b

With the upper and lower airbag brackets installed into place, the new Chassis Tech air bellow can be compressed similar to the front airbag compression and fitted into the rear brackets. Attach a 1/2-inch NPT air valve to the top of the bag as well as the supplied air lines to the brackets.
With the upper and lower airbag brackets installed into place, the new Chassis Tech air be
Now the proper pinion angle must be reestablished. Using a scaled pinion angle measuring tool, take an initial measurement from the bottom of the engine's crankshaft. Placing the tool on the lower pulley will work fine. Whatever the angle is, the pinion angle on the rearend needs to be set to the opposite. If the crankshaft angle is 4 degrees positive, the rearend pinion angle needs to be 4 degrees negative.
Now the proper pinion angle must be reestablished. Using a scaled pinion angle measuring t

One final measurement is needed to determine where the C-notch needs to be made. This is a critical step and one you do not want to mess up. Each measurement on both sides of the frame is determined prior to cutting.
One final measurement is needed to determine where the C-notch needs to be made. This is a
Now is the time to attach the Panhard rod, the only piece in the entire Chassis Tech air suspension four-link kit that is not a bolt-on item. However, the measurements are easy to determine, and minor welding will ensure the proper alignment of the truck's axle. The pivot point on the truck's frame can be established by mounting the Panhard rod to the axle pickup point, which does bolt-on.
Now is the time to attach the Panhard rod, the only piece in the entire Chassis Tech air s

With the Panhard bar lying as flat and parallel to the truck's axle as possible, the upper mount needs to be welded into place. With adjustable Heim joints, the axle can still be maneuvered from side to side to achieve the proper alignment.
With the Panhard bar lying as flat and parallel to the truck's axle as possible, the upper
All that remains at the rear is to notch the truck's frame for installation of the Super C-notch. Some careful calculation was made and the notch was marked out. Again, we elected to use a plasma cutter to make the cut, but you can use a cutoff wheel attached to a 3/8-inch or a 1/2-inch drill. The plasma cutter is just quicker.
All that remains at the rear is to notch the truck's frame for installation of the Super C

This is how the truck's frame looks after cutting out the section for the Super C-notch. As you can see, with this deep of a cut, the reinforcement plate on the saddle becomes necessary to maximize the truck's metallurgy.
This is how the truck's frame looks after cutting out the section for the Super C-notch. A
The Super C-notch can now be fitted to the truck's frame. It can either be bolted into place or welded into place. If you bolt the Super C-notch into place, use a stepped drill bit to make the proper holes in the frame so the mounting hardware can be installed and tightened to 45 lb-ft of torque.
The Super C-notch can now be fitted to the truck's frame. It can either be bolted into pla

During the entire installation process, we ran and properly secured all of the air lines up and away from moving parts, such as the suspension itself, and away from potential flying road debris. The 9-gallon V-twin air tank was mounted in the truck's bed, along with the four 75-cfm air valves. We chose to power the entire system with a pair of red-topped Optima batteries and ran another 12-volt hot line directly to the alternator to keep the batteries fresh and always available to make the truck dance on air.
During the entire installation process, we ran and properly secured all of the air lines u