Genuine Mazda 6-Speed Gearbox 3rd/4th Gear Clutch Hub Set • P610-17-240

Genuine Mazda 6-Speed Gearbox 3rd/4th Gear Clutch Hub Set

Replacement Genuine Mazda third- and fourth-gear clutch hub set for Mazda MX-5 Mk3.5 and Mk3.75 NC 2.0 Sport models fitted with the later six-speed manual transmission.

The clutch hub is splined to the transmission shaft and forms the central part of the third- and fourth-gear synchroniser assembly. Together with the sliding sleeve, synchroniser rings and selector fork, it allows either third or fourth gear to be selected and locked to the shaft.

When the gear lever is moved, the selector fork moves the synchroniser sleeve across the hub. The synchroniser components equalise the rotational speed of the selected gear before the sleeve engages, allowing a smooth and controlled gear change.

One third/fourth clutch hub set is fitted per transmission, and this listing supplies one Genuine Mazda hub set.

Important transmission restriction: P610-17-240 is for the later six-speed manual gearbox used in facelift Mk3.5 and Mk3.75 NC 2.0 Sport models. It should not be assumed suitable for the earlier pre-2009 six-speed gearbox, five-speed manual transmission or automatic transmission.

• Part type: Third- and fourth-gear clutch hub set
• Common names: 3rd/4th synchro hub / synchroniser hub / selector hub
• Mazda catalogue description: Hub Set, Clutch – 3rd & 4th
• Location: Internal six-speed manual gearbox assembly
• Gear positions served: Third and fourth
• Transmission application: Later six-speed manual gearbox
• Quantity fitted per gearbox: 1
• Quantity supplied: 1 clutch hub set
• Selector fork included: No
• Synchroniser rings included: Not confirmed; order separately unless physically supplied with the set
• Third and fourth gears included: No
• Transmission bearings included: No
• Brand: Genuine Mazda
• Part No.: P610-17-240
• MX-5 fitment: Mk3.5 and Mk3.75 NC 2.0 Sport six-speed manual

Possible signs of a worn or damaged hub assembly:

• Difficulty selecting third or fourth gear
• Gear grinding during third-to-fourth or fourth-to-third shifts
• Transmission jumping out of third or fourth gear
• Excessive movement or wear in the synchroniser sleeve
• Rounded or damaged engagement teeth
• Metal contamination in the transmission oil
• Damage following selector-fork or synchroniser failure

Fitment advice: Confirm the gearbox type and production specification before ordering. Later P610-series transmission components are not automatically interchangeable with the earlier six-speed gearbox components used in pre-facelift NC models.

Diagnosis advice: Poor third- or fourth-gear selection can also be caused by worn synchroniser rings, a damaged selector fork, worn gear engagement teeth, excessive shaft movement or incorrect transmission oil. The gearbox should be dismantled and inspected before individual components are selected.

Replacement advice: Inspect the synchroniser sleeve, third- and fourth-gear synchroniser rings, selector fork, gear engagement teeth, shaft splines, bearings and locking nuts. Components with corresponding wear should be renewed together to avoid damaging the replacement hub.

Other items to consider: Consider replacing the third/fourth selector fork, synchroniser rings, shaft locking nuts, transmission oil seals, relevant bearings and the specified manual transmission oil during a gearbox rebuild.

Useful tools / consumables: Transmission stand, bearing separator, suitable pullers and press equipment, circlip pliers, calibrated torque wrench, measuring equipment, clean assembly lubricant and the correct manual transmission oil.

Difficulty guide: DIY Difficulty: Specialist / Advanced. Replacement requires complete transmission removal and substantial internal gearbox dismantling. Correct component orientation, shaft clearances and locking-fastener procedures are essential.

Why Genuine Mazda? Genuine Mazda transmission components match the original shaft splines, synchroniser-sleeve geometry, engagement-tooth profile and material specification. Accurate matching between the hub, sleeve and synchroniser components is essential for smooth gear engagement and reliable operation.

What’s in the box: One Genuine Mazda third- and fourth-gear clutch hub set, part number P610-17-240.

Installation notes: Remove and dismantle the transmission using the applicable Mazda workshop procedure. Record the orientation and order of all gears, hubs, sleeves, rings, spacers and bearings during disassembly. Inspect the complete third/fourth synchroniser assembly and associated gears before fitting the replacement hub. Lubricate the components with clean transmission oil during assembly, verify that the synchroniser sleeve moves freely and install all locking components using the specified procedures. Confirm correct shaft end float and gear selection before the transmission casing is sealed and refitted.