Genuine Mazda Suspension Arm Ball Joint Dust Boot • F151-28-4B3

Genuine Mazda F151-28-4B3 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 from entering its bearing surfaces.

A split or displaced boot can allow grease to escape and abrasive contamination to enter the joint. If caught early, a serviceable joint may be cleaned, inspected and regreased before fitting a new boot. A joint with corrosion, stiffness, roughness or excessive movement requires replacement of the applicable complete suspension arm.

On the MX-5 NC, this boot is used at the front upper control-arm and rear toe-control-arm ball joints. The same component fits left- and right-hand positions.

Four boots are used across the vehicle: two at the front upper control arms and two at the rear toe-control arms. This listing supplies one Genuine Mazda boot.

Position distinction: The upper rear trailing arms and main lower lateral links use the different Mazda boot F151-28-503. Identify the affected arm and joint before ordering.

• Part type: Suspension-arm ball-joint dust boot
• Common names: Ball-joint rubber boot / control-arm dust cap / suspension joint cover
• Mazda catalogue description: Boot, Dust
• Applicable front position: Front upper control-arm ball joints
• Applicable rear position: Rear toe-control-arm ball joints
• Position: Left- or right-hand
• 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.: F151-28-4B3
• Alternative boot for other rear arms: F151-28-503
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC models

Possible signs of a damaged dust boot:

• Visible split, tear or cracking in the rubber
• Grease leaking from the ball joint
• Boot displaced from its seating groove
• Water, rust or dirt visible around the joint pin
• Suspension creaking or stiffness
• Ball-joint movement caused by prolonged contamination
• Damage discovered during suspension inspection or dismantling

Fitment advice: This boot fits specific ball joints within the original MX-5 NC multilink suspension. It is used at the front upper control arms and rear toe-control arms. Do not assume that it fits every suspension-arm joint on the vehicle.

Joint inspection: Once separated, move the ball-joint pin through its normal range and inspect 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, the alternative F151-28-503 rear-arm boots, suspension-arm bushes, mounting bolts, alignment adjusters and anti-roll-bar drop links. A wheel alignment may be required if adjustable suspension fasteners are disturbed.

Useful tools / consumables: Vehicle lift or axle stands, socket and spanner set, calibrated torque wrench, suitable ball-joint separator, pick tools, 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 then be seated evenly and securely without tearing it.

Why Genuine Mazda? Genuine Mazda suspension boots 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 normal travel.

What’s in the box: One Genuine Mazda suspension-arm ball-joint dust boot, part number F151-28-4B3.

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 appropriate 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 install the replacement boot without twisting or damaging its sealing edges. Confirm that it is fully seated before reconnecting the suspension. Tighten all fasteners to the applicable Mazda specification and arrange a wheel-alignment check where alignment settings have been disturbed.