Buick Grand National Suspension Parts: Upgrades and Replacement Guide

The Buick Grand National is a legendary performance car from the mid-1980s. Its turbocharged V6 and rear-wheel-drive layout make it a favorite among enthusiasts. However, the suspension components on these cars are now decades old, and finding the right parts for restoration or upgrade is crucial. Whether you are replacing worn-out parts or building a track-day machine, understanding the suspension system and available options helps you make informed decisions.

Why Upgrade or Replace Your Buick Grand National Suspension?

Original suspension parts on a Grand National were designed for a balance of comfort and handling, but after 30-plus years, rubber bushings harden, springs sag, and shocks lose damping. This leads to poor ride quality, excessive body roll, and vague steering. Upgrading to modern components can transform the car's behavior without compromising daily drivability.

Common Signs of Worn Suspension

• Nose dive under braking
• Excessive body lean in corners
• Bouncy or harsh ride over bumps
• Steering wheel vibration or wandering
• Uneven tire wear

If you notice any of these, it's time to inspect and replace parts.

Key Suspension Components for the Grand National

The suspension system includes several critical parts. Here's a breakdown of what each does and what to look for when replacing.

Shocks and Struts

Front: The Grand National uses coil-over struts up front. Rear: It uses separate shocks and coil springs. Aftermarket options include gas-charged shocks for improved damping, adjustables for tuning, and coil-over conversions for the rear.

• Standard Replacement: Monroe or KYB gas shocks restore stock feel and are budget-friendly.
• Performance Upgrades: Bilstein and Koni offer monotube shocks with better heat dissipation and control.
• Adjustable Shocks: QA1 and Viking allow you to dial in compression and rebound settings for street or track.

Springs

Front springs are part of the strut assembly; rear springs are separate. Over time, springs settle, lowering ride height and reducing load capacity.

• Stock Replacement: Moog or AC Delco springs maintain factory ride height and rate.
• Lowering Springs: Eibach and Hotchkis offer progressive-rate springs that lower the car about 1 to 1.5 inches for a sportier stance and reduced body roll.
• Coil-Over Kits: For full adjustability, coil-over conversions like UMI Performance or Ridetech allow spring preload and height adjustment.

Control Arms and Bushings

Control arms connect the chassis to the wheels. The Grand National has upper and lower control arms in the rear and lower control arms in the front (part of the strut). Worn bushings cause alignment issues and sloppy handling.

• Rubber Bushings: OEM-style replacements are quiet and absorb vibration but wear faster.
• Polyurethane Bushings: Energy Suspension and Prothane make poly bushings that reduce deflection and improve steering response. They transmit more road noise.
• Adjustable Control Arms: Brands like Spohn and BMR offer tubular arms with rod ends for precise alignment settings, ideal for drag racing or autocross.

Sway Bars

Sway bars reduce body roll during cornering. Upgrading to thicker bars can significantly improve handling.

• Stock Replacement: N/A – no major aftermarket for stock bars.
• Performance Bars: Addco and Hellwig offer front and rear bars that are 1.25 to 1.375 inches thick, often adjustable for stiffness.

Steering and Tie Rods

Worn tie rods cause loose steering and uneven tire wear. Replace inner and outer tie rods with heavy-duty units.

• Stock: Moog or AC Delco.
• Performance: Some upgrade to tubular tie rod adjusters for easier alignment.

Choosing the Right Parts: Street vs. Performance

Your driving style dictates the parts you need.

For Daily Driving and Comfort

• Stick with quality shocks like Monroe or KYB and stock-height springs.
• Replace bushings with rubber to maintain a quiet ride.
• Keep stock sway bars or upgrade to a moderate thickness like 1.125 inches.
• Use standard tie rods and alignment settings.

For Enhanced Handling and Occasional Track Use

• Upgrade to Bilstein or Koni shocks.
• Install lowering springs (1 inch drop) to lower center of gravity.
• Swap bushings for polyurethane in critical areas like lower control arms.
• Add a 1.25-inch front sway bar and a 7/8-inch rear bar.
• Use adjustable rear upper control arms to set pinion angle.

For Drag Racing

• Focus on weight transfer and traction. Use adjustable shocks (e.g., QA1) with soft settings for launch.
• Rear coil-over conversion to adjust height and preload.
• Solid control arm bushings or rod ends to prevent deflection.
• Air bags inside rear springs to assist with launch.
• No front sway bar or a very small one.

Installation Tips and Considerations

Replacing suspension parts on a Grand National requires basic mechanical skills and proper tools. Here are some tips:

• Always replace in pairs: Shocks, springs, and bushings should be replaced on both sides.
• Alignment required: After any suspension work, get a professional alignment to ensure even tire wear and stable handling.
• Check torque specs: Over-tightening polyurethane bushings can cause binding. Follow manufacturer instructions.
• Jack stands: Use sturdy jack stands and never work under the car supported only by a jack.
• Consider rust: Northern cars may have rusty bolts. Use penetrating oil and heat carefully.

Final Recommendation

For most Grand National owners, a balanced upgrade package makes the most sense. Start with Bilstein shocks, Moog springs (stock height or 1-inch drop), polyurethane bushings on the front lower control arms and rear sway bar, and a 1.25-inch front sway bar. This combination sharpens handling without ruining ride comfort. If you plan to hit the strip often, add adjustable rear control arms and a rear coil-over kit. Always consult part compatibility for your specific year (1984-1987) as some parts differ. With the right parts, your Buick Grand National will drive like a modern sports car while keeping its classic appeal.