Mustang 5 Leaf Spring Kit (1967-1968) Installation Instructions

Tools Required:
  • Safety Glasses
  • Floor Jack
  • Jack Stand
  • Wheel Chocks
  • Socket Wrench/Combination Wrenches (numerous sizes)
  • Penetrating Oil
  • Hammer
  • Drift
  • Torch
Install Difficulty:
  • Moderate
  • Moderate Project
1. To start installing your new Mustang 5 Leaf Spring Kit, spray all existing bolts with penetrating oil 2 or 3 days before you plan to start the job. This will help loosen up the rusted hardware.
Mustang 5 Leaf Spring Kit Install Image
2. After 2-3 days, when you're ready to start the job, begin by blocking the front wheels using wheel chocks.
3. Loosen the lug nuts on both rear Mustang wheels. Do not remove them yet.
4. Using a floor jack, jack up the rear of the car until the tires are off the ground. Place jack stands under the frame, just in front of the forward leaf spring mount.
5. Remove both rear wheels.
6. Lower the car back down so it rests on the jack stands.
7. Using the floor jack again, place it under the housing of the Mustang rear axle and raise it slightly to take the weight off of the springs.
8. Using a 9/16 inch deep socket, remove the lower shock bolt from the shock plate, then remove the Mustang shocks.
9. Using an 11/16 inch wrench, remove the four nuts from the U-bolts, then remove the U-bolts and shock plate.
10. Using two 1/4 inch wrenches, loosen and remove the nut which holds the front of the Mustang spring in place.
Mustang 5 Leaf Spring Kit Install Image
11. Using the hammer and drift, punch the bolt back out of the hole. If you’re lucky and used the penetrating oil, it should come right out. If not, you may need to use the torch to heat it up prior to removal. Removing these bolts could become a major fight. Remember, if at first you don’t succeed, try, try again.
12. Once the bolt is removed, lower this end of the leaf spring to the ground.
13. Using two 9/16 inch wrenches, loosen and remove the bolt holding the Mustang rear shackles to the frame. Using the hammer and drift, punch the bolt back out of the hole and lower the leaf spring to the ground.
14. Remove the old shackle bushings in the frame member.
15. Repeat on the other side.
16. The only part not supplied with the spring kit is the shock plate. At this point, I took the time to clean up the existing shock plate and painted it with Mustang Eastwood Red Rust Encapsulator.
17. Remove all new parts from the box, lay them out and check against the packing list to insure you have all the parts before assembly. NOTE: I have never had an issue with missing parts bought at CJs.
18. My kit contained the following parts:
a. (2) Leafs springs
b. (4) U-bolts and nuts
c. (2) Sets of shackles including nuts
d. (8) Bushing halves
e. (2) Front mounting bolts
Mustang 5 Leaf Spring Kit Install Image
19. Next, I pre-assembled all of the parts off of the car to make sure they all fit. This is not a necessary step.
Mustang 5 Leaf Spring Kit Install Image
20. To begin installing the leaf springs on the car, insert the front mounting bolt into the frame hole from the inside, raise the end of the leaf spring into place, and continue inserting the bolt until it comes out the other side.
Mustang 5 Leaf Spring Kit Install Image
21. Start the nut on the treaded end, then, using two 1/4 inch wrenches, tighten the nut which holds the front of the leaf spring in place.
Mustang 5 Leaf Spring Kit Install Image
22. Next, I sprayed the rear shackle bushing with a little bit of silicon spray so the parts will assemble a little easier.
Mustang 5 Leaf Spring Kit Install Image
23. Insert two of the bushing halves in the rear eyelet of the spring, as well as in the frame rail holes.
Mustang 5 Leaf Spring Kit Install Image
24. Raise the Mustang spring into place and insert the shackles into the eyelet end frame bushing.
Mustang 5 Leaf Spring Kit Install Image
25. Start the nut on the treaded end of the bolts that hold the rear shackles to the frame. Using a 9/16 inch wrench, tighten both nuts.
Mustang 5 Leaf Spring Kit Install Image
26. Now it is time to reinstall the lower shock plate. Place the Mustang U-bolts over the axle housing and through the lower shock plate. Start the nuts on the bolt and hand tighten. NOTE: Insure that the shock plate is properly installed and the bolt in the spring comes through the shock plate.
Mustang 5 Leaf Spring Kit Install Image
27. Using an 11/16 inch wrench tighten the Mustang leaf spring hardware on the U-bolts.
Mustang 5 Leaf Spring Kit Install Image
28. Reinstall the lower end of the shock into the hole on the Mustang shock plate. Install the nut using a 9/16 inch deep socket and tighten the bolt on the shock plate.
29. Repeat on the other side of the car.
30. At this point, go back and insure that all the nuts and bolts are tightened.
Mustang 5 Leaf Spring Kit Install Image
Mustang 5 Leaf Spring Kit Install Image
31. Reinstall the wheels and snug up the lug nuts
32. Jack up the rear of the car remove the jack stands and lower the car back down on its wheels
33. Just tighten all of the lug nuts to complete the installation of your new Mustang 5 Leaf Spring Kit!