3-second answer: Sagging rear = tired leaf springs (or broken leaves — look for a snapped leaf under the clamps). Options: add-a-leaf (~$100, raises ~1-2 in, firmer) or new spring packs (~$250-450/side, the right fix). Broken main leaf = replace now; it's a safety item.
Diagnose
- Measure the fender gap side to side and front to rear.
- Look UNDER the pack for a broken leaf (the classic: the shortest leaves snap at the clamp).
- A sagging pack that still has all its leaves = tired steel — replace or add-a-leaf.
- Broken or cracked leaf = replace that pack immediately.
Add-a-leaf vs replacement
| Option | Cost | Result |
|---|---|---|
| Add-a-leaf | ~$100 | +1-2 in lift, firmer ride. Fine for load support, not a rebuild. |
| New pack | ~$250-450/side | Restores factory ride/height. The right fix. |
| Helper airbags | ~$150-250 | Air-assist for towing; doesn't fix sag. |
The job
- Support the axle on stands; the pack unbolts at the front hanger, shackle, and center pin.
- New U-bolts (they stretch — never reuse with new springs), new bushings.
- Torque the U-bolts after the truck is on the ground with weight on the springs (the right sequence).
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Threads
- FTE search: leaf spring · sagging