Genuine Mazda Rear Suspension Arm Ball Joint Dust Boot • F151-28-503

Genuine Mazda F151-28-503 Rear Suspension Arm Ball Joint Dust Boot

Replacement Genuine Mazda suspension-arm ball-joint dust boot for Mazda MX-5 Mk3, Mk3.5 and Mk3.75 NC models with 1.8 or 2.0 petrol engines.

The flexible rubber boot fits over the suspension-arm ball joint. It retains grease around the joint while helping prevent water, road salt, grit and other contaminants entering the bearing surfaces.

A split or displaced boot can allow grease to escape and abrasive contamination to enter the joint. If caught early, the joint may be cleaned, inspected and regreased before a replacement boot is fitted. A joint with corrosion, stiffness or excessive movement should be replaced with the complete suspension arm.

On the MX-5 NC, this boot is used on the upper rear trailing-arm and main lower lateral-link ball joints. The same component fits left- and right-hand positions.

Four boots are fitted across the applicable rear suspension joints, and this listing supplies one Genuine Mazda boot. Select a quantity of four when replacing every applicable boot on the vehicle.

Position note: A different boot is used on the rear toe-control arm and certain other suspension joints. Identify the affected arm and joint before ordering.

• Part type: Suspension-arm ball-joint dust boot
• Common names: Ball-joint rubber boot / lateral-arm dust cap / suspension joint cover
• Mazda catalogue description: Boot, Dust
• Location: Rear suspension-arm ball joints
• Applicable arms: Upper rear trailing arms and main lower lateral links
• Position: Left- or right-hand rear
• Handed component: No
• Function: Retains grease and protects the ball joint from contamination
• Quantity fitted per vehicle: 4 across the applicable joints
• Quantity supplied: 1 boot
• Ball joint included: No
• Suspension arm included: No
• Grease included: No
• Retaining clip included: Only where physically supplied
• Brand: Genuine Mazda
• Part No.: F151-28-503
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC models

Possible signs of a damaged dust boot:

• Visible split or tear in the rubber
• Grease leaking from the joint
• Boot displaced from its seating groove
• Water or dirt visible around the ball-joint pin
• Dryness, cracking or deterioration of the rubber
• Suspension creaking or stiffness
• Ball-joint play caused by prolonged contamination

Fitment advice: This boot fits specific rear suspension-arm ball joints on the original MX-5 NC multilink suspension. It is used on the upper rear trailing arms and main lower lateral links. It should not automatically be substituted for the boots fitted to the toe-control arms or other joints.

Joint inspection: Once separated, move the ball-joint pin through its normal range and check for roughness, stiffness, corrosion or excessive free play. Replacing the rubber boot alone is appropriate only where the underlying joint remains serviceable.

Other items to consider: Inspect the remaining three applicable boots, rear suspension arms, toe-control links, mounting bolts, alignment adjusters and anti-roll-bar drop links. A full wheel alignment may be required if adjustable suspension fasteners are disturbed.

Useful tools / consumables: Vehicle lift or axle stands, socket and spanner set, torque wrench, suitable ball-joint separator, circlip or pick tools where required, cleaning solvent and compatible high-quality ball-joint grease.

Difficulty guide: DIY Difficulty: Moderate. The ball-joint taper must be released without damaging the pin, arm or surrounding components. The replacement boot must be seated evenly and securely without tearing it.

Why Genuine Mazda? Genuine Mazda suspension boots are manufactured to match the original joint diameter, seating grooves, movement range and rubber profile. Correct dimensions help the boot remain sealed while the suspension moves through its full travel.

What’s in the box: One Genuine Mazda rear suspension-arm ball-joint dust boot, part number F151-28-503.

Installation notes: Raise and support the vehicle safely before releasing the affected suspension joint. Mark any adjustable mounting positions that may be disturbed. Separate the ball-joint taper using suitable tooling without striking or damaging the threaded pin. Remove the damaged boot, clean away old grease and contamination and inspect the joint carefully. Apply compatible fresh grease, then fit the replacement boot without twisting or damaging its sealing edges. Confirm that it is fully seated around the joint and arm before reconnecting the suspension. Tighten all fasteners to the applicable Mazda specification at the prescribed suspension position and arrange a wheel-alignment check where alignment settings have been disturbed.