Spring - F-450 & F-550: Installation

WARNING: This page is about a different car, the 2006 Ford Pickup, 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

If removed, install the auxiliary spring.
1. Position the auxiliary spring spacer.
2. Position the auxiliary spring.
3. Position the upper spring plate.
4. Install the auxiliary spring nut and tighten to 80 Nm (59 lb-ft).

CAUTION: Final tightening of the spring-to-shackle nut must be done with the suspension at curb height.

Position the rear spring shackle onto the spring and install the spring-to-shackle nut and bolt until snug.

CAUTION: Final tightening of the shackle-to-rear bracket bolt must be done with the suspension at curb height.

Position the rear spring assembly and install the shackle-to-rear bracket bolt and flag nut until snug.

CAUTION: Final tightening of the spring-to-front bracket bolt must be done with the suspension at curb height.

Install the spring-to-front bracket bolt and flag nut until snug.

CAUTION: Final tightening of the U-bolt nuts must be done with the suspension at curb height.

Install the U-bolts, springs plate 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 spring-to-shackle nut to 225 Nm (166 lb-ft).
With the suspension at curb height, tighten the shackle-to-rear bracket bolt to 225 Nm (166 lb-ft).
With the suspension at curb height, tighten the spring-to-front bracket bolt to 625 Nm (444 lb-ft).
With the suspension at curb height, tighten the 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).