installation instructions

gt4 front axle lift kit

***DBJ is not responsible for damage to you or your vehicle by installing our products. Avoid improper installations that can lead to damage by using a professional for all installations***

**These instructions are meant as a guide and will not cover the suspension in full detail**

*It is recommended to have your car realigned and corner balanced since you will be adjusting the ride height and camber settings during this install*

Suggested tools

10mm socket

13mm socket

18mm socket

19mm socket 

21mm socket

2.5mm allen socket

5mm allen socket

9/32" or 7mm allen socket

9mm wrench

10mm wrench

16mm wrench

21mm wrench

T20 torx

T30 torx

Coilover Spanner wrenches

Impact driver

Torque wrench

Box cutter

Wire stripper


Phillips screwdriver

Zip tie cutters

Included hardware and parts

4x M4X14 Screws

3x M8X20 Screws

3x M8 Washers

1x Ring Terminals

1x Male Spade Terminal

4x Female Spade Terminal

1x Compressor mounting bracket

2x Suspension spacers

16 gauge wire

Zip ties

Suspension Preparation

Although the front springs are easily removed and replaced without pulling out the entire front strut, we will need more clearance to fit the air cups over the strut. Be careful during steps 6-9. The suspension when disconnected (loosened) may drop. Support the brake and wheel carrier from falling during this phase.

1. Start by removing the front wheels and removing the front cowl underneath the hood. (19mm socket)

2. Disconnect the suspension levelers on both sides (9mm and 10mm wrench)

3. Loosen brake line brackets (10mm wrench)

4. Disconnect swaybar from drop links (tools depend on aftermarket or OEM sizing)

5. Loosen the lower spring perches (spanner wrenches)

6. Remove toe link bolt (18mm socket & 16mm wrench) 

7. Remove lower control arm bolt (18mm socket). This step is optional. It is possible to lower the suspension enough to slip on the air cup without removing the the LCA

8. Remove top strut bolt (Impact 21mm socket or break with 21mm wrench and 9/32" allen)

9. Remove camber plate bolts (13mm socket)

Install Aircups

1. Once the suspension is loosened and the strut has enough clearance, remove the OEM spring top hat. The OEM spring top hat consists of 2 parts and a white spacer. We will not be reusing these parts.

2. If you are changing the spring, this is the time to do it. Else continue with the stock spring.

3. This maybe a good time to mark your spring perch locations as a reference point. If you would like the same ride height on oem springs, lower the spring perches approximately 15mm to 20mm. Please leave enough threads for the spring perch to lock. Note that there maybe limitations to this as the OEM shock has a finite amount of threads. If you wish to set the ride height lower, you may need to upgrade the springs.

4. Take the original dust boot and cut a larger hole for the strut diameter. This is so the dust boot does not get caught between the spring and the aircup. The dust boot should sit below the aircup and between the spring and strut piston. 

5. Slide the air cup over the springs and strut. The inside should receive the spring nicely. We found the best routing position for the air hosing is by facing the inlet towards the front of the car. There is a path for the pressure hose to go into the battery area without drilling or even removing fender lining.

6. Insert the suspension spacer above the air cup as shown in the photo on the left.

7. Install the camber plate above using the 21mm nut to complete the assembly. 

Reinstall Suspension parts

1. Lift the suspension back into place. 

2. Reinstall the camber plate bolts.

3. Reinstall the lower control arm if removed.

4. Reinstall the toe link.

5. Reinstall the suspension levelers.

6. Reinstall the brake line brackets.

7. Reinstall the droplinks to the swaybars. If the ride height has changed, these will need to be adjusted to compensate. Swaybars are supposed to be installed with 0 preload at static ride height.

8. Tighten all bolts back to factory torque specs.

9. Tighten the spring perch to desired height setting. (This will be an iterative process to determine your desired ride height and corner balancing)

Prepare Compressor

Remove the rear cap at the compressor inlet port shown in the bottom left picture. Next install the air filter puck onto the compressor. The puck is shown in the bottom middle picture. There is a spare air filter included.(bottom right)

install compressor

1. Remove the emergency tire pump by removing the two screws circled in red in the picture above (T20 Torx)

2.  Remove the factory bolt in the location marked with a green circle in the bottom left picture(13mm socket)

3. Install compressor mounting bracket with the supplied (3) M8x20 Screws and (3) M8 washers. You can see the hole locations in the bottom left picture (5mm allen)

4. Install compressor onto mounting bracket using the supplied M4 screws. The blue and yellow circles in the middle picture indicate the location of these screws (2.5mm allen)

setup the electrical wiring

Follow the electrical diagram to the left to wire up your lift kit. Use crimps to secure the spade terminals and ring terminals to the wires. Once the wiring is completed, the wireless relay can be attached to the compressor mounting bracket via zip ties. Use two of the holes circled in red in the right most picture above.

Please note that the 3-way valve solenoid will have 3 terminals. Please use only the two as shown in the picture to the right.

route the pressure hosing

The diagram to the left shows the hose routing. The lines going to the air cups should be easy to poke through the top of the fender lining without the need to cut or drill any holes. Use a box cutter to cleanly cut the ends so they will fit into the valves without leaking. It is a good idea to test the system for leaks by making a circle with the hosing on the T-valve. We discovered a loose fitting on the 3-way valve which was easily fixed by tightening the fitting with a wrench. When the system is turned on, the compressor should stop automatically once a pressure level is reached (pressure switch activated). When the pressure falls below a certain point, the compressor will reactivate. This cycle will happen if there is a leak in the closed system. Check for audible leaks before finishing. Once no leaks are confirmed, attach the aircups to the system. 

Due to the macpherson suspension design, the air cups will turn when the steering wheel is turned. When attaching the air hoses to the air cups, turn the steering wheel full lock one direction. Check to make sure the lines are not crimped and turn full lock the opposite direction. Make sure the air hoses are installed in such a way that no crimping or tight turns are made when the car transitions from full lock to full lock.

The picture to the left illustrates the hosing setup for the 3way valve. The top side is where the compressor line enters, and the bottom is where the hosing should leave and enter the T fitting. From there, the air hoses will connect to the aircups.

final items

Once everything is hooked up properly, we recommend using supplied zip ties to secure the wires and hoses to the chassis. Make sure the hose does not contact the tire or crimp when driving and during turns. Ensure that wires are not excessively bent and not contacting metal surfaces. Check to see that the pressure switch and 3-way valve are also securely restrained to the sides. Reinstall the front cowl and wheels. Take your car out for a test drive and enjoy the lift kit!