ACT 19-25 Mazda MX-5 Miata HD/Perf Street Rigid Clutch Kit

The ACT ZM15-HDSD is a rigid-hub street and track clutch for the 2019-2025 Mazda MX-5 Miata and Miata RF with the 2.0L engine and six-speed manual, the later ND car often called the ND2. Owners shopping it usually fall into two camps: the factory clutch has started to slip or judder after autocross weekends and track days, or the car is getting a lighter flywheel and the owner wants the quickest, lightest street disc ACT makes for it. It is the rigid-hub sibling of ACT's sprung ZM14 kit, and the difference between the two is the whole buying decision.

What this clutch kit does in a 2019-2025 MX-5

The kit replaces the friction parts that couple the 2.0L to the gearbox. ACT pairs its MZ033 Heavy Duty pressure plate, which uses a stronger diaphragm for more clamp load and less deflection, with the 3000211 Performance Street rigid disc. That disc uses a copper-rich organic facing on a steel-backed lining for burst strength, riveted to a heat-treated chromoly hub with no damper springs. ACT rates the kit at 312 ft-lb at the crank, which it lists as 46 percent more torque capacity than the original clutch, on a 224 mm (8.8 in) disc with a 0.9375 in input spline.

Without springs in the hub, the rigid disc is ACT's lightest street disc, so it spins down faster and shifts feel quicker. The trade-off is noise and wear: ACT describes the feel as light to moderate pedal effort with smooth engagement but increased gear rattle, and notes the rigid design may increase spline wear. On a daily-driven car that sits in traffic, the sprung version is usually the better choice. On a car that sees track sessions and runs a lighter flywheel, the rigid hub is what many owners want.

Symptoms that point to a worn clutch

• Revs rise on a full-throttle pull in third or fourth while road speed lags behind
• Judder or shudder pulling away, often worse once the car is fully hot after a session
• A burnt friction smell after launches, hill starts or back-to-back autocross runs
• The engagement point creeping toward the top of the pedal travel
• A chirp or growl that changes when the pedal is pressed, pointing to the release or pilot bearing

How to confirm it before you buy

Run a slip test: in fourth gear around 2,500 rpm, go to full throttle and watch whether the tach climbs faster than the speedometer. Our slipping diagnosis guide covers that test step by step. Before you pull the transmission, check the clutch fluid level and bleed the system, since air or a weak slave cylinder can mimic a failing clutch; our clutch bleeding guide shows how. Look for oil at the bellhousing seam too, because a leaking rear main seal will soak any new disc.

Fitment

This kit fits the 2019-2025 Mazda MX-5 Miata 2.0L, soft top and RF, and ACT's application list for ZM15-HDSD carries the 2.0L through the 2026 model year. It does not fit the 2016-2018 ND1, which uses a different clutch; those cars take the ACT ZM10-HDSS. Automatic cars are not covered. ACT notes the kit must be used with the original Mazda flywheel or an ACT flywheel, and the flywheel is not included. If you want the flywheel and a sprung disc in one box, the ACT ZM14-HDSS kit with flywheel covers the same years. If you are not sure which ND you own, send us the year and VIN before ordering. More clutch kits are in our rebuild kits collection.

Install notes

• In the box: MZ033 pressure plate, 3000211 rigid disc, RB110 release bearing, PB1030 pilot bearing and AT05 alignment tool. ACT also includes the M8-1.25 x 20 mm pressure plate bolts.
• Pull the old pilot bearing with a slide-hammer puller such as the OTC 1172 and install the new PB1030.
• Resurface or replace the flywheel, clean the friction face with brake cleaner, center the disc with the supplied tool and tighten the pressure plate bolts in a crossing pattern in steps.
• Refill and bleed the clutch hydraulics with fresh brake fluid of the type Mazda specifies on the reservoir cap.
• Break the clutch in gently for the first few hundred miles with normal stop-and-go driving before any launches or track work; see our break-in guide.

For the labor side of the job, our manual repair cost guide and the Miata clutch cost by generation page help you budget. The ZM15-HDSD is new, in stock, ships the same business day from the USA and carries a 1-year warranty.

Does ZM15-HDSD fit a 2016-2018 MX-5?

No. ACT lists it for the 2019 and later MX-5 Miata 2.0L. The 2016-2018 cars use a different clutch, such as ACT's ZM10 kits. Send us your year and VIN if you are unsure which ND you have.

Is a flywheel included?

No. ACT says this kit must be used with the original Mazda flywheel or an ACT flywheel. If you want a flywheel in the box, the ZM14-HDSS kit includes ACT's Streetlite flywheel.

Rigid or sprung: which should I buy?

The rigid disc is lighter and shifts faster, but ACT notes more gear rattle and possible extra spline wear. For a car that mostly drives on the street, the sprung disc is smoother. For a track or autocross car, the rigid hub is the common pick.

How much holding power does it have?

ACT rates the kit at 312 ft-lb at the crank, 46 percent over the factory clutch. That covers a stock or lightly modified 2.0L with plenty of margin.

Will the pedal get heavier?

ACT describes Heavy Duty pressure plate pedal effort as light to moderate, so the pedal is firmer than stock but still comfortable for daily driving.

What comes in the kit?

The MZ033 pressure plate, 3000211 rigid disc, RB110 release bearing, PB1030 pilot bearing, AT05 alignment tool and M8 pressure plate bolts.

• Transmission Slipping Diagnosis Guide
• Automatic vs. Manual Transmission Repair Cost
• Shift Flare vs. Slip: How to Tell the Difference