Genuine Mazda Track Rod Adjustment Locking Nut • NE51-32-137

Genuine Mazda Track Rod Adjustment Locking Nut

Replacement Genuine Mazda track-rod adjustment locking nut for all Mazda MX-5 Mk3, Mk3.5 and Mk3.75 NC models with 1.8- or 2.0-litre petrol engines.

This nut is fitted to the threaded steering-rack inner tie rod immediately behind the outer track-rod end. Once the track-rod end has been rotated to establish the correct front toe setting, the nut is tightened against it to lock the adjustment in position.

A secure locking nut helps prevent the track-rod end from moving along the threaded inner tie rod during normal steering and suspension operation. If the nut is loose, damaged or unable to clamp correctly, the wheel-alignment setting may change.

The same nut is used on both the left- and right-hand sides. Two are fitted per vehicle, while this listing supplies one Genuine Mazda locking nut.

• Part type: Track-rod adjustment locking nut
• Common names: Track-rod lock nut / tie-rod jam nut / toe-adjustment nut
• Mazda catalogue description: Nut, Lock
• System: Steering rack and linkage
• Installation position: Between the inner tie rod and outer track-rod end
• Function: Locks the front toe adjustment after alignment
• Side application: Left or right
• Quantity fitted per vehicle: 2
• Quantity supplied: 1 nut
• Outer track-rod end included: No
• Inner tie rod included: No
• Steering-rack boot included: No
• Brand: Genuine Mazda
• Part No.: NE51-32-137
• Compact Mazda reference: NE5132137
• Associated outer track-rod end: NE51-32-280A
• Associated inner tie rod / rack end: NE51-32-240
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC

Typical reasons for replacement:

• Nut seized onto the inner tie-rod thread
• Hexagon rounded or damaged during adjustment
• Threads corroded, stripped or cross-threaded
• Nut damaged while removing a seized track-rod end
• Incorrect universal nut previously installed
• Outer track-rod end being replaced
• Inner tie rod being removed or renewed
• Nut no longer tightens securely against the track-rod end

Quantity advice: One locking nut is used on each front track rod. This listing supplies one nut; order two when replacing both sides.

Position advice: This is the adjustment lock nut fitted between the inner tie rod and outer track-rod end. It should not be confused with the separate self-locking nut securing the track-rod-end ball-joint pin to the steering knuckle.

Alignment advice: Record the exposed thread length or original track-rod-end position before dismantling to provide an approximate starting point. A professional wheel alignment is required after disturbing the track-rod adjustment.

Thread inspection: Inspect the inner tie-rod and track-rod-end threads before installing the new nut. A replacement locking nut will not repair damaged, heavily corroded or cross-threaded components.

Replacement advice: Ensure the nut runs freely on the correct section of thread before fitting the track-rod end. Do not force the nut over damaged threads.

Tightening advice: Establish the correct front toe setting, hold the track-rod end or inner tie rod as required and tighten the nut firmly against the track-rod end using the applicable Mazda workshop procedure.

Other items to inspect: Check the outer track-rod end, inner tie rod, steering-rack boot, boot retaining clips, steering-knuckle connection and corresponding components on the opposite side.

Useful tools / consumables: Open-ended spanners, penetrating fluid, wire brush, thread-cleaning tools, calibrated torque wrench where applicable and professional wheel-alignment equipment.

Difficulty guide: DIY Difficulty: Moderate. Access is straightforward, but seized steering threads can make removal difficult and the front wheel alignment must be checked after installation.

Why Genuine Mazda? Genuine Mazda steering hardware matches the original thread, nut dimensions and track-rod adjustment arrangement. Correctly fitting hardware helps retain the intended wheel-alignment setting without damaging the steering threads.

What’s in the box: One Genuine Mazda track-rod adjustment locking nut, part number NE51-32-137.

Installation notes: Raise and support the vehicle safely where required. Mark or measure the original track-rod-end position before loosening the existing nut. Clean and inspect the exposed threads, then install the replacement nut and refit or adjust the track-rod end. Set the front toe using suitable alignment equipment and tighten the locking nut against the track-rod end using the applicable Mazda procedure. Confirm that the steering operates freely before road use.