Ford F-150/F-250: How To Add a Leaf to Leaf Springs

Adding a leaf to the springs on the rear of your truck is a trick as old as trucks. That extra leaf will give your F-150 or F-250 an improved payload capacity and a few inches of lift in the back.

By Brett Foote - October 15, 2014
Contributors: 99offroadrngr

Adding a leaf to your truck's leaf springs is a popular, easy, and inexpensive way to achieve a 1.5 - 3" lift in the rear and add 900 or more pounds of towing capacity to your truck. Add-a-leaf kits generally cost between $75 and $250 depending on the exact model of your truck, and take one to two hours to install.

Figure 1. Typical leaf spring. The individual slabs of metal are called leaves. Bounded together, they make a leaf spring that will give your truck added spring and height in the back.

Installing a leaf requires a moderate level of skill, as leaf springs are under pressure and can be dangerous if removed improperly. Professional installation can cost around $300-$400 and is highly recommended if you are unsure of your ability to accomplish the task.

Tools Needed

  • Floor jack
  • Two jack stands
  • 1/2" deep socket set
  • Impact gun (preferred) or 1/2" ratchet and breaker bar
  • Air hammer (or hammer and punch)
  • C-clamps
  • New U-bolts (if your kit doesn't include them)

Step 1 - Lift truck

Lift rear of vehicle with automotive jack. It should be strong enough to lift your truck (at least a 6 ton jack is recommended). Lift using the center differential until the truck is high enough that the wheels have clearance from the ground. Support the truck by jack stands placed underneath the frame.

Figure 2. Get the rear of the truck in the air the way you're most comfortable. In this photo, the truck is lifted by rear differential. The jack stands will support the frame while sitting on the ramps (see Figure 2).

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Step 2 - Support rear axle

Once the truck is supported by jack stands, lower the rear axle. Make sure to keep the axle supported by the jack, however. It should not be hanging in the air by the leaf springs. Remove the upper and lower bolts on your shock absorbers and pull them out of the wheel well.

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Figure 3. Support the truck on jack stands. Lower axle until there is no stress on the shock absorbers. Then disconnect them.

Step 3 - Remove u-bolt and hardware

Remove axle u-bolt and bracket. This will leave the center bolt as the only part connecting the axle to this leaf spring.

  • Figure 4. The u-bolts of this F-150 are highlighted in red. The bracket securing the u-bolts to the axle is highlighted in yellow.
  • Figure 5. After the u-bolts an bracket have been removed, you're left with the center nut.

Step 4 - Clamp leaf spring and remove center bolts

Use C-clamps to hold spring assembly together. Remove center bolt(s) with socket . Hammer and punch may be needed if bolt is rusted.

Figure 4. Remove the center bolt while the clamps are holding the springs together. The socket sitting on the leaf spring is where the center bolt is located.

Step 5 - Install add-a-leaf

Remove C-clamps (carefully) and reassemble leaf spring with add-a-leaf in place. Add small amount of grease to each end.

Figure 5. The additional leaf should slot between the lowest leaf spring and the flat helper spring. It's highlighted in the photo above by a red border.

Step 6 - Reassemble suspension

Assemble completed spring assemblies loosely into axle mounts. Replace center bolt, U-bolts, brackets, nuts. Torque to factory specifications. Re-install the wheels last.

Figure 6. The new leaf spring has been installed.

Step 7 - Test drive

Lower vehicle and take for a test drive to ensure proper installation. The suspension will feel a little to a lot stiffer in the rear thanks to the extra springs, but it should not be noisy. If you hear creaking and cracking or any other signs of mechanical distress, examine your springs for a clear signs of trouble. Cracked leaves, broken brackets and badly aligned springs are good examples. The simple nature of this install and the suspension of these trucks means you probably won't have to worry about this—still, it's better to be safe than sorry.

  • Figure 7. Slipped leaf spring
  • Figure 8. The middle leaf is broken on this truck.
  • Figure 9. Leaf spring shackle that has rusted through.

Featured Video: How to Add a Leaf to Leaf Springs

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