555-8126 Steeda Mustang Rear Coilover System (2005-2014)

Shop This Part Now: Steeda Mustang Rear Coilover System (2005-2014)

Rear Coilover System 

NOTE: Installation of this kit requires above average mechanical skills. This procedure should only be undertaken by a competent individual with the necessary skills to properly complete the installation. We strongly recommend that a factory shop manual be available for reference during the installation. If you are not confident you can complete the job safely, have the work performed by a certified technician who is familiar with the suspension of a Mustang. Failure to reassemble the suspension properly can lead to serious injury. 


1. Measure the vehicles initial ride height to get a baseline. Check the height at all four wheels. Be sure to check the height on level ground. 

2. Raise the entire vehicle. If working from the floor, secure with jack stands. Remove the front wheels. Unhook all attachments to the front struts (i.e.; Brake lines, Sway bar links, etc.) 

3. Remove both front strut assemblies. Each strut is secured by four nuts on top of the strut tower and two lower 14mm bolts. First remove the two lower bolts; it may be helpful to support the brake/spindle assembly with a jack. Once loose, secure the brake/spindle assembly, so there is no tension on the brake line. Next, hold the strut assembly and carefully remove the four top nuts. It may be helpful to have a second set of hands to hold and remove the strut assembly while removing the nuts. (Pic. 1,2)  

4. Caution: Coil springs store a tremendous amount of energy. Failure to properly remove and install the springs can lead to severe injury. 

5. Using a coil spring compressor, compress the front spring until there is no tension on the upper strut mount. Once the spring is safely secured, remove the nut holding down the upper strut mount. Then separate the strut from the spring and the upper strut mount. Carefully release the stock spring and remove the OE bump stop from the shaft of the strut. 

(See attached addendum before proceeding) 

6. Assemble the Steeda Front Coilover. Slide the OE bump stop over the shaft of the new coilover strut followed by the spring, spacer, and new upper strut mount assembly. (Pic. 4) Secure the entire assembly with the provided 16mm locking nut to 40-45 lb/ft. Do not use an impact wrench and do not over tighten. Note, grease the threads of the spring seat to ease ride height adjustment. Use the provided grease for the urethane bushings only!  

7. Attach the new upper strut mount back to the car with the 4 new nuts on top of the strut tower. The bolts on the studded bracket should pass through the slots on the slotted bracket and then through the 4 holes of the strut tower from the bottom up. The Steeda Logo should face the outside of the vehicle. (Pic. 3) 

8. Install both of the lower 14mm bolts. Tighten both bolts to Ford specification and replace all auxiliary attachments (i.e.; Brake lines, Sway bar links, etc.). Use Lock-Tight when reinstalling the swaybar endlinks. 


9. With the car still raised, remove the rear wheels. 

10. Using a floor jack underneath the differential, gently support the weight of the rear axle assembly. Do not raise the vehicle any higher with the floor jack. (Pic. 5) 

11. Remove the 2 nuts on each side of the vehicle that secure the factory bushing clamps and sway bar to the axle assembly. Swing the sway bar to the rear of the vehicle and out of the way. 

12. Remove the lower bolts connecting both shocks to the rear axle assembly. (Pic. 6) Once removed, carefully lower the rear end until the springs are free and can be removed. Do not lower the axle to the point that there is any tension in the brake lines.

13. Install the new Steeda adjustable billet seats. Remove OE lower rubber spring gasket. Slide the studded washer beneath the lip of the remaining spring seat on the axle as shown. (Pic. 7) Then, slide the billet seat over the stud with the open end up. (Pic. 8) Secure the seat with the provided nut. From beneath the OE spring seat on the axle, push a screwdriver into the opening as shown to stop the bolt from spinning while tightening. (Pic. 9) Grease the threads of the spring seat to ease ride height adjustment. Repeat for the opposite side. 

14. Reuse the upper rubber spring seat and the new Steeda lower spring seat, to secure the new Steeda spring in position.  

15. Remove the OE rear shocks. From the trunk, pull away the carpeted side panels towards the rear of the trunk to reveal the upper strut mount. Remove the nut fastening the strut and remove. It is recommended that you have someone hold it to prevent the shock from falling to the floor as you remove the upper nut. Repeat for the opposite side. 

16. Install the new rear D-Spec shocks. From underneath the car have someone place the D-spec shock into position as you secure the upper nut. 

17. Carefully re-raise the rear axle assembly and then reconnect the shocks and sway bar. 

18. Replace all four wheels and carefully lower the vehicle. Roll the vehicle back and forth a few times to settle the suspension. Then re-measure the ride height in the same position as your baseline. 

19. Using a spanner wrench adjust the ride height of both the front and the rear. Note it may be necessary to jack up the vehicle and remove the wheels to gain access to the adjustable spring perches. To adjust, turn the spring perch clockwise to raise the vehicle and counter clockwise to lower the vehicle. Lower the car and roll it back and forth a few times to settle the suspension. Recheck the vehicle ride height and repeat if necessary. Once the desired position is obtained, lock the perches in position using the allen-head set screw on the lower spring seats. 

20. Carefully test drive the vehicle in a controlled environment. Then recheck all fasteners to be sure everything is secure.

All installation instructions, images, & descriptions contained within are representative of the manufacturer instructions included with your part upon purchase & are the sole property thereof.
Pure Speed Motorsports practices due diligence in reviewing these instructions for accuracy and recommends consulting a certified professional when installing any aftermarket part or accessory.