Suspension & Steering
No Shortcuts Here

Ball Joints & Track Rod Ends

Ball joints are among the most safety-critical components on a classic car, and among the most frequently fitted with substandard replacements. A cheap ball joint with a thin-walled housing and inferior grease will wear out in 15,000–20,000 miles on a car that should see 80,000 between replacements.

When sourcing ball joints, avoid unbranded catalogue parts. Buy from suppliers who specify the manufacturer. Quinton Hazell, TRW, and Moog are established brands for classic British and European applications. The original equipment suppliers — Cam Gears, Adwest, and Burman — produced the OEM components; NOS from these suppliers commands a premium and is worth it.

Track rod ends (tie rod ends) follow the same logic. Wear is detectable by grasping the rod and checking for free play at the ball joint. Any detectable slop means replacement. Always check and replace as a pair — if one is worn, the other is close behind.

Rubber & Polyurethane Bushes

Bush failure is the most common cause of imprecise steering feel on a classic car that passes a ball joint check. The bushes connecting the wishbones and sub-frames to the body degrade over decades, becoming hard and cracked or soft and spongy — both conditions produce vague handling and accelerated wear on other components.

Rubber bushes are period-correct, absorb vibration well, and require no maintenance. They are appropriate for comfort-oriented restorations and concours cars.

Polyurethane bushes are stiffer, last significantly longer, and resist oil contamination. They transmit more road noise and vibration into the cabin, and require periodic greasing to prevent squeal from metal-to-polyurethane contact. They are appropriate for driver's cars and light competition use.

Fitting a complete bush kit — all suspension and subframe bushes in one pass — is far preferable to replacing individual bushes as they fail. The cost difference is small; the alignment consistency benefit is significant.

Dampers & Springs

Original lever-arm dampers fitted to most British sports cars of the 1950s–70s (MGB, Triumph TR series, Jaguar E-Type) were effective when new but have typically been out of production for decades. Rebuilding is possible and preferable for concours cars; for drivers, modern gas-charged telescopic units offer significantly better performance.

Conversion kits for lever-arm to telescopic are available for most British classics from suppliers including Spax and Gaz. These kits maintain original mounting points and retain the factory ride height. Spax adjustable units allow progressive damping tuning — a genuine improvement for a well-used driver.

Spring rate is a separate consideration. Most classics were designed for cross-ply tyres and benefit from slight spring softening when running modern radials to maintain correct contact patch behaviour. Consult a specialist before changing spring rates.

Steering Racks & Boxes

Rack and pinion steering (used on most classic European sports cars) wears at the pinion bearing and at the rack bushes. Symptoms are a straight-ahead dead spot, inconsistent return-to-centre, and clonking over bumps.

Rebuilt racks are available for most common applications. When buying a rebuilt unit, ask specifically about the pinion preload adjustment — a poorly adjusted pinion is the most common cause of "heavy centre" steering on a freshly rebuilt rack.

Recirculating ball steering boxes (common on older British cars and American classics) are more complex to rebuild but have a longer service life. Adjustment is possible on most units to reduce play without requiring a full rebuild — but this should only be done by someone familiar with the specific box geometry, as over-tightening causes binding.

Wheel Bearings

Taper roller wheel bearings — standard on most classic cars — are robust but require correct preload setting during assembly. Overtightening causes rapid wear and heat build-up; too loose causes handling imprecision and bearing brinelling under cornering loads.

Use premium bearings from SKF, Timken, or FAG. For most classic applications, these are still in production. Avoid unbranded bearings for wheel applications — the geometry tolerance requirements are tight.

Sealed modern sealed hub bearings (press-fit, non-adjustable) have been retrofitted to some classic applications for ease of maintenance. This is a legitimate choice for high-mileage drivers but is not period-correct and cannot be run-in the traditional way.

Common Pitfalls

• Fitting without alignment: Any suspension work — even replacing a single bush — can alter geometry. Always have alignment checked after any suspension component replacement.
• Ignoring the subframe: Many classic cars have front subframes that rust from the inside. A structurally compromised subframe makes all suspension geometry moot. Inspect before spending money on components.
• Cross-ply vs radial tyres: Many classics were set up for cross-ply tyres. Running radials on factory cross-ply geometry produces different camber and caster behaviour. A small alignment correction usually improves things significantly.
• Pattern ball joints: Some unbranded ball joints have housings machined to a lower specification than OEM, resulting in premature wear. Pay slightly more for a named manufacturer.
• Greasing polyurethane bushes: Polyurethane bushes must be greased with a suitable non-petroleum grease (most polyurethane bush kits include suitable grease). Standard petroleum grease swells and degrades polyurethane.

Recommended Suppliers