Genuine Mazda Front Upper Suspension Arm / Wishbone – LH • NH42-34-250

Genuine Mazda NH42-34-250 Left-Hand Front Upper Suspension Arm / Wishbone

Replacement Genuine Mazda left-hand front upper suspension arm for Mazda MX-5 Mk3, Mk3.5 and Mk3.75 NC models, including fabric soft-top and Power Retractable Hard Top vehicles.

The upper suspension arm connects the upper section of the left-hand front wheel hub carrier to the front subframe. It helps locate the wheel accurately while allowing controlled vertical suspension movement and steering articulation.

The two inner rubber bushes permit the arm to pivot as the suspension moves, while the integrated upper ball joint connects the outer end of the arm to the steering knuckle.

Together, these components help maintain the intended wheel position, camber geometry and front-end control. Wear or distortion can affect steering precision, tyre wear and the vehicle’s ability to retain correct wheel alignment.

This is a complete left-hand arm assembly supplied with its inner bushes and upper ball joint already installed. One left-hand upper arm is fitted per vehicle. Mounting bolts, nuts and alignment work are not included.

• Part type: Front upper suspension arm assembly
• Common names: Upper wishbone / upper control arm
• Mazda catalogue description: Arm (L), Upper
• Position: Left-hand front
• UK position: Nearside front
• Handed component: Yes
• Inner suspension bushes included: Yes
• Upper ball joint included: Yes
• Mounting bolts and nuts included: No
• Quantity fitted in this position: 1
• Quantity supplied: 1 complete arm assembly
• Body-style compatibility: Fabric soft top and PRHT
• Brand: Genuine Mazda
• Part No.: NH42-34-250
• Replaces: NE51-34-250A and NE51-34-250B
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC models

Possible signs of a worn or damaged upper arm:

• Knocking or clunking from the left-hand front suspension
• Movement or play in the upper ball joint
• Split, separated or deteriorated inner bushes
• Uneven or accelerated front tyre wear
• Imprecise steering or reduced front-end stability
• Wheel alignment moving outside specification
• Arm bent following kerb, pothole or accident damage
• Corrosion or damage around the bush or ball-joint housings

Fitment advice: This listing is for the left-hand front upper arm. Confirm the required side before ordering. The vehicle should retain the original Mazda NC front subframe, steering knuckle and suspension arrangement.

Other items to consider: Inspect the right-hand upper arm, lower suspension arms, ball joints, inner bushes, shock absorber, spring, anti-roll bar links and all associated mounting hardware. Replace any bolt or nut with stretched, damaged or heavily corroded threads.

Useful tools / consumables: Suitable socket and spanner set, breaker bar, ball-joint separator, calibrated torque wrench, penetrating fluid, suspension support equipment and suitable marking tools for recording the original component positions.

Difficulty guide: DIY Difficulty: Advanced. The suspension and steering knuckle must be supported correctly during removal. Fasteners passing through bonded rubber bushes should receive final tightening at the specified normal ride-height position to avoid preloading the bushes.

Why Genuine Mazda? Genuine Mazda suspension arms are manufactured to match the original arm geometry, bush positions, ball-joint taper and mounting dimensions. Correct geometry is essential for maintaining the intended camber movement, wheel location and suspension operation.

What’s in the box: One Genuine Mazda left-hand front upper suspension arm assembly, part number NH42-34-250, complete with inner bushes and upper ball joint.

Installation notes: Raise and support the vehicle safely, then support the steering knuckle before disconnecting the upper ball joint and inner arm mountings. Inspect the mounting bolts, subframe brackets and steering-knuckle taper before fitting the replacement arm. Start all hardware by hand and tighten the ball-joint fastening to the applicable Mazda specification. Final-tighten fasteners passing through bonded rubber bushes with the suspension positioned at the specified normal ride height. Carry out a complete wheel-alignment check after installation.