Your car doesn't sit as high as it used to. Maybe one corner looks lower than the rest, or the ride feels rougher over bumps than you remember. These are signs your coil springs may be sagging and they're worth checking before the problem gets worse. Diagnosing coil spring sag yourself and adjusting ride height back to spec saves money, protects your tires and suspension components, and keeps your vehicle handling the way it was designed to.

What Does Coil Spring Sag Actually Mean?

Coil springs support the weight of your vehicle. Over thousands of miles and years of use, the steel in those springs fatigues. The coils gradually lose their free length and tension a process called sagging. When a spring sags, it can no longer hold the vehicle at the correct ride height. The body sits lower, which changes suspension geometry, alignment angles, and how the vehicle handles under braking and cornering.

A sagged spring isn't the same as a broken spring. A broken spring is obvious you'll hear clunking or see a visibly cracked coil. Sagging is sneaky. It happens so slowly that many drivers don't notice until tire wear gets uneven or the suspension starts bottoming out over speed bumps.

How Can I Tell If My Coil Springs Are Sagging?

There are a few reliable ways to check for spring sag at home with basic tools.

Measure Ride Height at Each Corner

Park the vehicle on a flat, level surface. Use a tape measure to check the distance from the center of each wheel hub to the fender lip (or from the ground to a specific point on the body, depending on your vehicle's service manual spec). Compare these measurements side to side and front to rear. If one corner is noticeably lower even by half an inch that spring has likely lost tension.

For a more detailed walkthrough on measuring correctly after replacing springs, you can check your ride height measurements and correction steps.

Look at Tire Wear Patterns

Sagging springs change camber and toe angles. If the inside or outside edge of a tire is wearing faster than the rest, and your alignment checks out, a weak spring may be allowing the suspension to sit at the wrong angle under load.

The Bounce Test

Push down firmly on one corner of the vehicle and release. Count how many times it bounces before settling. If it bounces more than twice, the spring (or shock absorber) isn't controlling movement well. This test alone won't confirm sag, but combined with a height measurement it adds useful evidence.

Check for Uneven Gaps

Squat behind the car or stand in front and look at the wheel-to-fender gap on both sides. Uneven gaps are a visual red flag. Also look for common signs of worn-out coil springs that cause harsh ride and bottoming out, since sagging often shows up alongside those symptoms.

What Tools Do I Need for This Job?

You don't need a full shop to diagnose sag. Here's what helps:

• Tape measure for checking ride height at each corner
• Jack and jack stands to safely lift the vehicle if you need to remove wheels for inspection
• Service manual or spec sheet to find your vehicle's factory ride height measurements
• Notepad or phone to record measurements for comparison
• Spring compressor only if you plan to remove and replace springs (use caution; these can be dangerous if misused)

How Do I Adjust Ride Height After Finding Sag?

Once you've confirmed one or more springs have sagged, you have a few options depending on your setup and budget.

Replace the Sagged Springs

The most straightforward fix. New springs restore the factory ride height. Always replace springs in pairs both fronts or both rears so the vehicle sits evenly. Replacing just one side leads to uneven handling and premature wear on the new spring.

Use a Ride Height Correction Kit

If your vehicle has been lowered or if you want a budget-friendly way to compensate for mild sag, a ride height correction kit can help with lowered suspension and bottoming out issues. These kits typically include spacers or adjustable components that bring the ride height back without full spring replacement. They work best for minor sag if the springs are badly fatigued, replacement is still the better call.

Adjustable Coilovers

For vehicles with coilover suspension, you can adjust ride height by threading the spring perch up or down. This is a common setup on performance cars and trucks. Thread the perch to raise the corner that's sitting low, then re-measure to confirm the height matches the other side.

What Mistakes Should I Avoid?

• Measuring on uneven ground. Even a slight slope throws off your readings. Always use a flat, level surface like a garage floor.
• Replacing only one spring. The opposite spring has the same age and mileage. It's sagging too, even if it's less obvious. Replace in pairs.
• Ignoring alignment after spring work. Changing ride height changes alignment angles. Get an alignment check within a few hundred miles of any spring replacement or correction.
• Skipping the shock absorber check. Worn shocks can mimic or worsen sag symptoms. If your shocks have over 75,000 miles, inspect them while you're down there.
• Using generic spring specs. Your vehicle's ride height spec is specific to its model year, trim, and sometimes even its option package (sunroof, towing package, etc.). Don't guess look up the exact numbers.

How Often Should I Check for Spring Sag?

There's no universal schedule, but a good rule of thumb is to check ride height once a year or any time you notice the ride feels different. Vehicles that carry heavy loads, drive on rough roads, or have over 100,000 miles are more likely to develop sag sooner. If you're buying a used vehicle, measuring ride height should be part of your pre-purchase inspection.

Quick Diagnostic Checklist

1. Park on flat ground and let the suspension settle (drive around the block first, then park).
2. Measure hub-to-fender distance at all four corners.
3. Compare measurements to your vehicle's factory spec.
4. Look for differences of more than 1/2 inch between left and right sides.
5. Inspect tires for uneven wear.
6. Perform the bounce test at each corner.
7. If sag is confirmed, decide between spring replacement, a correction kit, or perch adjustment based on your setup.
8. After any correction, schedule a wheel alignment.

Tip: Write down your ride height measurements and the date. Over time, this gives you a personal baseline so you can catch gradual sag early before it causes tire damage or handling problems.