Spring - F-450, F-550: Installation

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

If removed, install the auxiliary spring in the following sequence.
1. Position the auxiliary spring spacer.
2. Position the auxiliary spring.
3. Position the upper spring plate.
4. Install the new auxiliary spring nut and tighten to 100 Nm (74 lb-ft).
NOTE: Final tightening of the spring-to-shackle nut must be done with the suspension at curb height or damage to the bushing may occur.

Position the rear spring shackle onto the spring and install the new spring-to-shackle nut and bolt until snug.
NOTE: Final tightening of the shackle-to-rear bracket bolt must be done with the suspension at curb height or damage to the bushing may occur.

Position the rear spring assembly and install the new shackle-to-rear bracket bolt and flagnut until snug.
NOTE: Final tightening of the spring-to-front bracket bolt must be done with the suspension at curb height or damage to the bushing may occur.

Install the new spring-to-front bracket bolt and nut until snug.
NOTE: Final tightening of the U-bolt nuts must be done with the suspension at curb height or incorrect clamp load may occur.

Install the new U-bolts, bottom cap and U-bolt nuts. Align the U-bolts so they are as vertical as possible and tighten the nuts until snug.
With the suspension at curb height, tighten the new spring-to-shackle nut to 225 Nm (166 lb-ft).
With the suspension at curb height, tighten the new shackle-to-rear bracket bolt to 225 Nm (166 lb-ft).
With the suspension at curb height, tighten the new spring-to-front bracket bolt to 515 Nm (340 lb-ft).
With the suspension at curb height, tighten the new U-bolt nuts evenly in a cross-type pattern in 4 stages.
- Stage 1: Tighten to 100 Nm (74 lb-ft).
- Stage 2: Tighten to 200 Nm (148 lb-ft).
- Stage 3: Tighten to 300 Nm (222 lb-ft).
- Stage 4: Tighten to 400 Nm (295 lb-ft).
Install the wheel and tire. For additional information, refer to WHEELS AND TIRES .