How to Install Air Lift Performance Suspension Kit - Rear (05-14 All) on your Ford Mustang

1. Tighten air spring lower stud mount into clamp plate hand tight.

2. Orient the air fitting with the hole/grommet for air line.

3. Insert air line through the chassis/grommet and into the air spring fitting

4. Locate air spring against the upper spring perch. Apply washer and nut to threads and torque to 10 lb.-ft.

PREPARING THE VEHICLE

1.    Support vehicle with jack stands or a hoist at approved lifting points. Support the axle at maximum extension

REMOVING THE STOCK SHOCK/SPRING

1.    Disconnect the stabilizer bar from the chassis (Fig. 2).

2.    For Convertible Models:

Disconnect the chassis support bracing that is underneath the axle (Fig. 3).

3.    With the axle supported, remove the lower shock bolts (Fig. 4).

4.    Lower the axle until the coil spring can be removed.

CAUTION: DO NOT HANG THE AXLE FROM THE DRIVESHAFT. OVEREXTENSION OF THE DRIVESHAFT CAN CAUSE DAMAGE.

5.    Remove the coil spring and rubber isolators (Fig. 5).

6.    Remove the retaining washer/isolator from the shock upper stud mount and remove the shock from the vehicle (Fig. 6).

1.    Drill through the center on the upper spring perch using a 13/32 drill bit.

2.    From inside the trunk, measure 1 3/8” away from the previously drilled hole, toward the outside of the vehicle. Mark this location. Drill a 1/2” hole at this position for the grommet/ air-line to go through (Fig. 7).

3.    Place the supplied nut plate with nut facing down inside the lower coil spring perch (Fig. 8).

4.    Place the plastic spacer (J) over the lower coil spring perch (Fig. 9).

5.    Remove the nut (E) and washer (D) from the air spring assembly. Thread the air spring into the lower nut plate and tighten by hand 1 turn. Make sure to orient the air-port with the previously drilled hole in the chassis.

CAUTION: OVER TORQUING OF THE NUT CAN RESULT IN FAILURE OF THE AIR SPRING AND WILL NOT BE COVERED UNDER WARRANTY.

6.    Install grommet (O) into the 1/2” hole and route the air-line through the trunk. Attach to the air spring.

7.    Unroll the air spring and seat against the upper spring land making sure the airline is not crushed or kinked against the chassis.

8.    Within the trunk, apply the larger washer (D) and nut (E) to the threaded stud (C). Torque to 14Nm (10 lb.-ft.). Be careful not to over-torque and bend the sheet metal.

9.    Cut the stock jounce bumper down to 1/3 it’s standard height (Fig. 10).

10.    Install the rear shocks into the upper shock mount.

11.    Lift the axle and reinstall lower shock eye bolt. Do not torque at this time.

12.    Reinstall the stabilizer end link to the chassis. Do not torque at this time.

13.    For Convertible Models:

Reinstall chassis support brace bolts (Fig.3).

14.    Fully compress the suspension using a jack. With the suspension compressed, review the best routing for the leader hose that is clear of all suspension components and axle. Routing should also allow for the suspension to extend without kinking or pulling the line tight or rubbing on other components. Following the brake line routing is often a good place to start. Check clearances to all other components.

15.    With the suspension fully compressed, take a measurement from the fender to some reference point – typically the center of the axle. Record this measurement as Max Compression.

16.    Cycle the suspension to Max Extension and record the measurement from the same reference points.

17.    Add ME and MC then divide by 2. Set the suspension to this point. This position will give 50% stroke in either direction and is a starting point for ride height (Fig. 13).

18.    With the suspension at this position torque the lower clevis bolt, upper and lower control arm bolts to manufacturer’s specifications (Table 1).

19.    Reinstall wheels; retake the Max Compression and Extension measurements from the fender to lower wheel lip. Recalculate the ride height at 50% stroke and set the vehicle to that height. Enjoy the new look and handling! Now go get an alignment at the preferred drive height.

The shocks in this kit have 30 settings, or “clicks”, of adjustable compression and rebound damping characteristics. Damping is changed through the shock rod using the supplied adjuster (Figs. 14 & 15) or a 3mm allen wrench.

Turn the adjuster clockwise and the damping settings are hardened. Turn the adjuster counterclockwise and the damping is softened.

Each shock is preset to “-18 clicks”. This means that the shock is adjusted 18 clicks away from full stiff. Counting down from full stiff is the preferred method of keeping track of, or setting, damping. This setting was developed on a 2005 Ford Mustang GT and may need to be adjusted to different vehicles and driving characteristics.

1.    Using the control system, set the vehicle height to the new custom ride height.

2.    If the custom ride height is lower than stock, we recommend loosening all pivot points (bolts, nuts) on any control arm, strut arm or radius rod that contains bushings. Once they have been loosened, re-torque to stock specifications.

NOTE: It may be necessary to cycle the suspension to loosen the bushing up from its mount. This will help re-orient the bushing at its new position and increase life of the bushings based on the custom ride height.

Your dampers have been pre-set at the factory to provide maximum drop height while maintaining adequate tire clearance to the air spring. If you wish to gain more extended height (lift), which is the same as reducing drop height, or want to lower the chassis further and there is still adjustment available at the lower mount, please use the following procedure:

1.    Support the vehicle with jack stands or a hoist at approved lifting points.

2.    Remove the wheel.

3.    Using the supplied spanner wrench, loosen the lower locking collar (Fig. 16).

4. Deflate the air spring to 0 PSI on the corner you are adjusting.

5.    Disconnect lower mount from suspension.

6.    Spin the lower mount to the desired location.

NOTE: Not all models will have further drop height available.

7.    Re-install lower mount to suspension and torque fasteners.

8. Tighten the lower locking collar to the lower mount using significant force.

CAUTION: WHEN ADJUSTING HEIGHT UPWARDS, MAKE SURE THAT THE DAMPER BODY ENGAGES ALL THE THREADS OF THE LOWER MOUNT (FIG. 17). WHEN ADJUSTING DOWNWARDS, MAKE SURE THERE IS ADEQUATE AIR SPRING CLEARANCE TO THE TIRE/WHEEL ASSEMBLY. CLEARANCE MUST BE CHECKED WITH SYSTEM FULLY DEFLATED AS WELL AS FULLY INFLATED TO ENSURE THAT NO RUBBING OCCURS. FAILURE TO MAINTAIN ADEQUATE CLEARANCE CAN RESULT IN AIR SPRING FAILURE AND WILL NOT BE COVERED UNDER WARRANTY.

CAUTION: DO NOT ADJUST HEIGHT BY SPINNING AIR SPRING ON DAMPER! DOING SO MAY CAUSE AN AIR LEAK AND COMPROMISE THE ASSEMBLY.

CAUTION: DO NOT CYCLE THE SUSPENSION WITH THE AIR LINE CONNECTED TO THE LEADER HOSE WITHOUT FIRST ADDING AIR SPRING PRESSURE. DOING SO MAY CAUSE THE AIR SPRING TO IMPROPERLY INFLATE (FIG. 18). IT IS SAFE TO CYCLE THE SUSPENSION TO CHECK FOR CLEARANCES ETC. WITH THE LEADER HOSE OPEN TO ATMOSPHERE (DISCONNECTED FROM AIR LINE).

BEFORE SETTING VEHICLE ON THE GROUND FOR THE FIRST TIME, IT IS VERY IMPORTANT TO INFLATE THE AIR SPRINGS TO AT LEAST 50 PSI. THIS WILL PREVENT ANY POSSIBILITY OF THE AIR SPRING KICKING OUT AND CAUSING A LEAK (FIG. 19).

CAUTION: MAKE SURE THE FRONT WHEELS ARE STRAIGHT WHEN DEFLATING AND REINFLATING AIR BAGS.

1. Inflate and deflate the system (do not exceed 125 PSI) to check for clearance or binding issues. With the air springs deflated, check clearances on everything so as not to pinch brake lines, vent tubes, etc. Clear lines if necessary.

2. Inflate the air springs to 75-90 PSI and check all connections for leaks.

3.    An Air Lift Air Management System such as 3H/3P is highly recommended for this product.

4.    Please familiarize yourself further with this product by reading the Product Use, Maintenance and Servicing section.

 Clearance test — Inflate the air springs to 75-90 PSI and make sure there is at least 1/2” clearance from anything that might rub against each air spring. Be sure to check the clearance at ride height and after vehicle alignment.

 Leak test before road test — Inflate the air springs to 75-90 PSI and check all connections for leaks. All leaks must be eliminated before the vehicle is road tested.

 Heat test — Be sure there is sufficient clearance from heat sources, at least 6” for air springs and air lines. If a heat shield was included in the kit, install it. If there is no heat shield, but one is required, call Air Lift customer service at (800) 248-0892.

 Fastener test — Recheck all bolts for proper torque.

 Road test — The vehicle should be road tested after the preceding tests. Inflate the springs to recommended driving pressures. Drive the vehicle 10 miles and recheck for clearance, loose fasteners and air leaks.

 Operating instructions — If professionally installed, the installer should review the operating instructions with the owner. Be sure to provide the owner with all of the paperwork that came with the kit.

 Overnight leak down test — Recheck air pressure after the vehicle has been used for 24 hours. If the pressure has dropped more than 5 PSI, then there is a leak that must be fixed. Either fix the leak yourself or return to the installer for service.

 Air pressure requirements — Regardless of load, the air pressure should always be adjusted to maintain adequate ride height at all times while driving.

 Thirty day or 500 mile test — Recheck the air spring system after 30 days or 500 miles, whichever comes first. If any part shows signs of rubbing or abrasion, it must be remedied immediately! Please consult installation manual and re-check your installation. Rubbing of any kind will cause failure and will not be covered under warranty. If professionally installed, the installer should be consulted. Check all fasteners for tightness.

NOTE: By following these steps, vehicle owners will obtain the longest life and best results from their air spring.

1.    Check the air pressure before driving.

2. Never inflate beyond 125 PSI.

3.    If you develop an air leak in the system, use a soapy water solution to check all air line connections, before deflating and removing the spring.

4.    When increasing load, always adjust the air pressure to maintain normal ride height. Increase or decrease pressure from the system as necessary to attain normal ride height for optimal ride and handling. Remember that loads carried behind the axle (including tongue loads) require more leveling force (pressure) than those carried directly over the axle.

CAUTION: FOR YOUR SAFETY AND TO PREVENT DAMAGE TO YOUR VEHICLE, DO NOT EXCEED MAXIMUM GROSS VEHICLE WEIGHT RATING (GVWR), AS INDICATED BY THE VEHICLE MANUFACTURER. ALTHOUGH YOUR AIR SPRINGS ARE RATED AT A MAXIMUM INFLATION PRESSURE OF 125 PSI, THE AIR PRESSURE ACTUALLY NEEDED IS DEPENDENT ON YOUR LOAD.

5.    Always add air to the springs in small quantities, checking the pressure frequently. Sleeves require less air volume than a tire and inflate quickly.

6.    Should it become necessary to raise the vehicle by the frame, make sure the control system is turned off before lifting.

TROUBLESHOOTING GUIDE

1. Leak test the air line connections, the threaded connection into the air spring, and all fittings in the control system.

2.    Inspect the air lines to be sure none are pinched. Tie straps may be too tight. Loosen or replace the strap and replace leaking components.

3.    Inspect the air line for holes and cracks. Replace as needed.

4.    Look for a kink or fold in the air line. Reroute as needed.

If the preceding steps do not solve the problem, it is possibly caused by a failed air spring — either a factory defect or an operating problem. Please call Air Lift at (800) 248-0892 for assistance.

TUNING THE AIR PRESSURE

Pressure determination comes down to three things — level vehicle, ride comfort, and stability.

1.    Level vehicle
If the vehicle’s headlights are shining into the trees or the vehicle is leaning to one side,
then it is not level. Raise the air pressure to correct either of these problems and level
the vehicle.

2.    Ride comfort
If the vehicle has a rough or harsh ride it may be due to either too much pressure or not
enough. Try different pressures to determine the best ride comfort. See Air Lift suggested driving air pressure.

3.    Stability
Stability translates into safety and should be the priority, meaning the driver may need
to sacrifice a perfectly level and comfortable ride. Stability issues include roll control,
bounce, dive during braking and sponginess. Tuning out these problems usually requires
additional air pressure, strut damping, or both.

CHECKING FOR LEAKS

1. Inflate the air spring to 80 PSI.

2. Spray all connections and the inflation valves with a solution of 1/5 liquid dish soap and 4/5 water. Spot leaks easily by looking for bubbles in the soapy water.

3. After the test, deflate the springs to the minimum pressure required to restore the system to normal ride height.

4.    Check the air pressure again after 24 hours. A 2-4 PSI loss after initial installation is normal. Retest for leaks if the loss is more than 5 PSI.

FIXING LEAKS

1.    If there is a problem with a swivel fitting:

a. Check the air line connection by deflating the spring and removing the line by pulling the collar against the fitting and pulling firmly on the air line. Trim 1” off the end of the air line. Be sure the cut is clean and square (see Fig. 21). Reinsert the air line into the push-to-connect fitting.

b. Check the threaded connection by tightening the swivel fitting another 1/2 turn. If it still leaks, deflate the air spring, remove the fitting, and re-coat the threads with thread sealant. Reinstall by hand tightening as much as possible and then use a wrench for an additional two turns.

2.    If the preceding steps have not resolved the problem, call Air Lift customer service at (800) 248-0892.