Genuine Mazda 4th Gear Synchronizer Ring • M516-17-26Y

Genuine Mazda M516-17-26Y 4th Gear Synchronizer Ring

Replacement Genuine Mazda 4th gear synchronizer ring for Mazda MX-5 Mk3 / Mk3.5 / Mk3.75 (NC) 5-speed manual gearbox applications listed in the compatibility table.

A synchronizer ring, also known as a synchro ring or baulk ring, helps match the speed of the selected gear during gear changes. It allows the synchronizer hub and gear to engage smoothly, reducing gear clash and helping restore a cleaner, more positive shift feel.

This part is used inside the manual gearbox and is commonly associated with 4th gear synchronizer operation on Mazda MX-5 NC 5-speed transmissions. It is an internal gearbox component and requires gearbox removal and strip-down to replace.

This part is commonly replaced during gearbox rebuilds, when the gearbox shows symptoms such as crunching into 4th gear, difficult 4th gear selection, poor shift quality, worn synchronizer friction faces, or damage found during inspection of the manual transmission gearset.

• Part type: Synchronizer ring / synchro ring / baulk ring
• Primary use: 4th gear synchronization in the manual gearbox
• Location: Inside manual transmission, synchronizer assembly
• Quantity per listed gear position: 1
• Brand: Genuine Mazda
• Part No.: M516-17-26Y
• Also referenced as: M5161726Y
• Supersedes / cross-references: M506-17-26Y / M5061726Y
• Primary Mazda application: MX-5 NC 5-speed manual gearbox, including N7 / N7S gearbox codes

Fitment advice: Designed for the Mazda MX-5 NC 5-speed manual gearbox applications listed in the compatibility table. This part is for manual gearbox internals and is not for automatic transmissions. For gearbox-swapped, previously rebuilt or competition-use vehicles, match the gearbox code and the synchronizer ring being replaced before final assembly.

Other items to consider: When changing this part, you may also want to consider purchasing related gearbox rebuild items such as other synchronizer rings, hub/sleeve components, bearings, circlips, selector fork components, input/output shaft seals, gearbox gaskets or sealant, fresh Mazda-approved gearbox oil and any damaged or worn gearset hardware found during inspection.

Useful tools / consumables: Transmission jack, socket set, torque wrench, circlip pliers, bearing pullers, press tools, clean assembly bench, gearbox oil, brake cleaner, lint-free cloths, marking tools and the Mazda workshop manual for gearbox strip-down and rebuild procedure.

Difficulty guide: DIY Difficulty: Advanced. Synchronizer ring replacement requires gearbox removal and internal gearbox disassembly. Correct inspection, orientation, clearance checks and reassembly procedure are critical for smooth gear engagement and gearbox reliability.

Why Genuine Mazda? Genuine Mazda synchronizer rings are manufactured to the original gearbox specification for correct friction material, cone angle, clearances and engagement feel. Using the correct Genuine Mazda part helps maintain shift quality, reduces the risk of premature wear and ensures compatibility with the Mazda synchronizer hub and gear assembly.

Why buy from Mazspec? Mazspec specialises in Mazda and MX-5 parts, including gearbox, driveline and service components. We source genuine Mazda parts through trusted OE channels and can help with related gearbox rebuild items, oils, seals and practical parts advice for the job.

What’s in the box: One Genuine Mazda synchronizer ring.

Installation notes: Inspect the mating gear cone, hub sleeve, selector fork, bearings and related gearbox components during rebuild. Replace any worn or damaged associated parts before final assembly. Refill with the correct gearbox oil and check gear selection operation before returning the vehicle to service.