99 Eclipse Suspension Parts: Complete Guide to Choosing and Installing

If you own a 1999 Mitsubishi Eclipse, you know it’s a sporty compact car that handles well when everything is tight. Over time, suspension components wear out, leading to a bouncy ride, uneven tire wear, or poor cornering. This guide covers the essential suspension parts for a 99 Eclipse—what they do, when to replace them, and how to choose between OEM, aftermarket, and performance options. Whether you’re restoring a daily driver or building a weekend warrior, this information will help you make smart decisions.

Key Suspension Parts for the 1999 Eclipse

The suspension system on the 99 Eclipse (2G model) includes many interconnected components. Here are the most common parts that need replacement or upgrading.

Struts and Shocks

The Eclipse uses struts in the front and shocks in the rear. Struts are a structural part of the suspension that also support the spring, while shocks dampen movement. Signs of worn struts/shocks include excessive bouncing, nose diving during braking, and fluid leaks. For replacements, you have three main choices:

• OEM replacement: Direct fit, same ride quality as factory. Ideal for daily driving.
• Aftermarket standard: Brands like Monroe or KYB offer affordable upgrades that last longer than OEM.
• Performance struts/shocks: Tokico, Koni, or Bilstein provide improved damping and handling for spirited driving or autocross.

Tip: Replace struts and shocks in pairs (both front or both rear) and consider installing new strut mounts and bump stops at the same time.

Coil Springs and Strut Assemblies

Coil springs support the vehicle’s weight and maintain ride height. Sagging springs cause poor handling and uneven tire wear. You can buy springs separately or get a complete strut assembly (spring pre-assembled on the strut) for easier installation. Options include:

• Stock height springs: Maintain original ride height.
• Lowering springs: Drop the car 1-2 inches for a sportier look and lower center of gravity. Brands like Eibach, Tein, and H&R are popular.
• High-rate springs: Increase stiffness for better cornering but can make the ride firmer.

Note: If you lower the car, you may need adjustable camber bolts to realign the suspension.

Control Arms and Ball Joints

The front lower control arms connect the frame to the steering knuckle. Worn ball joints cause clunking noises and play in the steering. On the 99 Eclipse, ball joints are often replaceable separately, but the control arm itself can also wear out. For the rear, there are trailing arms and lateral arms. Consider:

• Moog makes durable aftermarket control arms with greaseable ball joints.
• OEM arms are reliable but more expensive.
• Adjustable control arms are useful if you’ve lowered the car and need to correct alignment angles.

Sway Bars and Links

The front and rear sway bars reduce body roll during cornering. The end links (small links that connect the bar to the control arm) often wear out first, causing rattling. Upgrading to thicker sway bars with polyurethane bushings sharpens handling. Energy Suspension makes popular bushing kits.

Bushings

Rubber bushings in control arms, sway bars, and trailing arms deteriorate with age. Polyurethane bushings last longer and improve response, but they transmit more vibration. For a street car, quality rubber or a mix of poly in certain spots is recommended.

Steering Components

Tie rod ends and the steering rack mount also affect suspension feel. Loose tie rods cause wandering steering. Moog and OEM are good choices for tie rods. A worn steering rack mount can be replaced with a polyurethane insert.

How to Choose the Right Parts

Determine Your Use Case

First, ask yourself what you want from the car:

• Daily driver: Stick with OEM-grade struts/shocks and standard springs. Comfort and longevity matter most.
• Enthusiast street: Consider performance shocks (e.g., Tokico Illumina) and mild lowering springs (1.0-1.5 inches drop).
• Track/autocross: Coilovers are the best investment. They allow adjustability in ride height, damping, and sometimes camber.

Budget vs. Quality

You can replace a worn strut with a $40 part, but it may fail quickly. Mid-range aftermarket (KYB, Monroe) offers a good balance for most owners. For high-performance, expect to pay $150-300 per strut. Coilovers range from $500-$1500 for a set.

Compatibility Notes for the 99 Eclipse

The 1995-1999 Eclipse (2G) shares suspension parts across trim levels (RS, GS, GST, GSX) but with differences:

• GSX (AWD): Rear suspension is different from FWD. AWD uses independent rear suspension with toe arms and upper control arms.
• Non-GSX models: Front suspension is similar for all FWD versions, but rear brakes and hubs vary. Always verify part fitment using your VIN or by checking your specific model year and drivetrain.

Installation Tips

Replacing suspension parts can be done at home with basic tools, but some jobs require special equipment (like spring compressors for struts). If you’re not experienced, have a professional install critical safety components like struts and ball joints. After any suspension work, get a wheel alignment to prevent premature tire wear.

Final Recommendation

For most 99 Eclipse owners, a smart upgrade path is:

1. Replace worn struts and shocks with KYB Gas-A-Just (rear) and KYB GR-2 (front) for a factory-like ride with better control.
2. If the car is lowered, use Eibach Pro-Kit springs with stock struts (or upgrade to Koni Yellows for adjustable damping).
3. Replace all rubber bushings with polyurethane where feasible (sway bar, control arm inner bushings) for crisper feel.
4. Always use new hardware and torque to spec.

Take care of the basics first—bushings, struts, and tie rods—before chasing performance upgrades. A well-maintained stock suspension handles great; worn parts will ruin even the best aftermarket components.

Keep your 99 Eclipse safe and fun by choosing quality suspension parts that match your driving style. Whether you’re cruising or carving corners, the right setup makes all the difference.