Trailer leaf springs take a beating over time. Heavy loads, rough roads, corrosion, and everyday wear can eventually cause springs to sag, crack, or break. Replacing worn leaf springs helps restore ride quality, improve towing stability, and reduce uneven tire wear.
If you’re replacing trailer springs, it’s also a good time to inspect—or replace—other suspension components like equalizers, shackles, spring bolts, and bushings, since worn hardware can quickly wear out new springs.
Here’s a step-by-step guide to changing trailer leaf springs.
Signs Your Leaf Springs Need Replacement
You may need new leaf springs if you notice:
- Sagging trailer height
- Broken spring leaves
- Cracked or bent springs
- Uneven trailer stance
- Rough ride quality
- Uneven tire wear
- Suspension noise or clunking
Damaged springs can affect weight distribution and towing safety.
Tools & Supplies Needed
Before starting, gather:
- Floor jack (rated for trailer weight)
- Heavy-duty jack stands
- Wheel chocks
- Socket and wrench set
- Breaker bar or impact wrench
- Penetrating oil
- Pry bar
- Torque wrench
- Replacement leaf springs
- New spring bolts & locknuts (recommended)
Optional but highly recommended:
- New equalizers
- Shackles or shackle straps
- Wet bolt kit
- Bushings
Step 1: Park on Level Ground & Secure the Trailer
Park the trailer on a flat, stable surface.
Before lifting:
- Chock the wheels securely
- Disconnect from tow vehicle if needed
- Ensure the trailer cannot move
Safety is critical when working on suspension systems.
Step 2: Lift the Trailer Properly
Jack the trailer under the frame—not the axle.
Raise the trailer enough to remove weight from the suspension.
Place heavy-duty jack stands under the frame and allow the axle to hang slightly.
You may also place a small jack under the axle to support it during spring removal.
Step 3: Remove the Wheels
Remove the lug nuts and wheels for easier access to suspension components.
This makes spring bolts, shackles, and equalizers much easier to reach.
Step 4: Inspect the Suspension System
Before removing anything, inspect:
- Equalizers
- Shackles or shackle straps
- Spring bolts
- Wet bolts
- Bushings
- Hangers
If parts show excessive wear, now is the best time to replace them.
Consider Replacing These Parts Too
Equalizers:
If worn, cracked, or elongated at the bolt holes, a bad equalizer can contribute to odd tire wear and poor suspension movement.
Shackles & Shackle Straps:
Thin or stretched shackles are very common wear items and can fail over time.
Spring Bolts / Wet Bolts:
Old bolts often seize, wear, or become damaged during removal.
Bushings:
Worn nylon or bronze bushings create excessive suspension movement and uneven tire wear.
Replacing these parts during spring service can save time and labor later.
Step 5: Remove the Old Leaf Spring
Support the axle slightly with a jack.
Remove:
- U-bolts holding the axle to the spring
- Front spring bolt
- Rear shackle bolts or slipper spring mount
Carefully remove the old spring.
You may need penetrating oil or a breaker bar if hardware is rusted or seized.
Step 6: Install the New Leaf Spring
Install the new spring in the same orientation as the old one.
Attach:
- Front spring eye bolt first
- Rear shackle or slipper mount
- Equalizer connection (if applicable)
Leave bolts slightly loose until everything is aligned.
Step 7: Reinstall the Axle & U-Bolts
Position the axle back onto the spring seat.
Install:
- U-bolts
- Tie plate
- Nuts
Always use new U-bolts when possible.
Old U-bolts stretch over time and may not torque properly.
Tighten evenly in a crisscross pattern.
Step 8: Tighten Suspension Hardware Correctly
Once everything is installed:
- Lower the trailer enough to place weight on the suspension
- Torque bolts to manufacturer specifications
Do not overtighten spring eye or shackle bolts.
Suspension components must move freely during travel.
If using wet bolts, grease all fittings after installation.
Step 9: Reinstall Wheels & Test
Reinstall wheels and torque lug nuts properly.
Take a short test drive and inspect:
✔ Proper ride height
✔ Smooth suspension movement
✔ No unusual noises
✔ Even trailer stance
Recheck hardware after several miles of towing.
Replace More Than Just the Springs?
Many trailer owners replace the following together:
✔ Leaf springs
✔ Equalizers
✔ Shackles
✔ Wet bolts
✔ Bushings
✔ U-bolts
Replacing worn suspension hardware at the same time helps improve ride quality and prevents premature wear on new springs.
Keep Your Trailer Suspension Road-Ready
Worn leaf springs can cause poor towing, uneven tire wear, and suspension problems. Replacing them—and inspecting related suspension parts—helps keep your trailer towing smoothly and safely.
At Highway Trailer Company, we carry replacement leaf springs, equalizers, shackles, wet bolt kits, bushings, U-bolts, and suspension hardware to help keep your trailer road-ready.