How to Install Maximum Motorsports Rear Ride Height Adjusters w/ Helper Springs (05-14 All) on your Ford Mustang

Read all instructions before beginning work. Following instructions in the proper sequence will ensure the best and easiest installation. 

1. Raise the vehicle and support it using jack stands beneath the pinch welds of the rocker panels.

WARNING: The vehicle must be lifted and supported under the rocker panel pinch welds (as specified in the Ford service manual) to avoid damage to the chassis.

2. Remove the rear wheels.

3. Disconnect the rear swaybar endlinks where they attach to each frame rail using a 15mm socket.

4. Support the passenger side of the axle housing using a floor jack. Place the floor jack just inboard of the control arm mounting bracket, onto the axle housing.

5. Remove the bolt retaining the brake hose bracket to the frame rail.

6. Remove the bolt/nut retaining the passenger side lower shock eyelet to the axle. Retain the hardware for later use.

7. Slowly lower the floor jack until the spring tension is released. 

8. Remove the passenger side spring and lower spring isolator from the axle housing.

9. Jack the passenger side of the axle up until the lower shock eyelet lines up with the shock mount on the axle housing.

10. Place the eyelet of the shock into the shock mount on the axle, and install the shock eyelet mounting bolt from the inboard side of the lower shock mount.

NOTE: The shock eyelet mounting nut will be installed later in these instructions.

11. Lower the floor jack and repeat Steps 4 to 10 on the driver side. 

12. Thread a spring perch onto each threaded sleeve until it bottoms out against the base of the threaded sleeve.  Make sure the raised lip on each spring perch faces upwards.

13. Place one of the rear coil-over springs on each spring perch.

14. Place one spring coupler on top of each of the coil-over springs.

15. Place one helper spring on top of each of the spring couplers.

16. Take one of the spring assemblies and insert it into the spring pocket on the bottom of the passenger side frame rail. Make sure the tip of the rubber isolator, located in the pocket, gets inserted into the center of the helper spring.

17. Pushing the spring upwards will compress the tender spring.  Once the tender spring is compressed, slide the bottom of threaded sleeve over the spring register on the top of the passenger side of the axle housing.

NOTE: For 8” or longer springs, it will be easier to remove the lower shock eyelet bolt and temporarily lower the axle housing using a floor jack to install the spring assembly. 

18. Repeat Steps 16 to 17 for the driver side of the vehicle. 

Rear Installation Completion 

19. Install the shock eyelet mounting nut and torque the lower shock eyelet bolts to 115 Nm (85 lb-ft) using a 15mm socket.

20. Reattach the brake hose brackets removed in Step 13 and torque the mounting bolts to 20 Nm (177 lb-in).

21. Reconnect the rear swaybar endlinks to the frame rail mounting brackets and torque the mounting nuts to 115 Nm (85 lb-ft) using a 15mm socket.

22. Reinstall the rear wheels and safely lower the vehicle to the ground.

23. Torque the lug nuts to the factory specifications.