Genuine Mazda Lower Power Plant Frame PPF to Differential Mounting Stud • 9YA9-0A-401

Genuine Mazda 9YA9-0A-401 Lower Power Plant Frame PPF to Differential Mounting Stud

Replacement Genuine Mazda lower Power Plant Frame mounting stud for Mazda MX-5 Mk3, Mk3.5 and Mk3.75 NC models.

The Power Plant Frame, commonly abbreviated to PPF, is the rigid structural member connecting the gearbox to the rear differential. It helps maintain the intended alignment between the transmission and differential while transmitting drivetrain loads through the vehicle.

This stud screws into the lower section of the differential housing and provides one of the threaded mounting points used to secure the differential end of the Power Plant Frame.

The PPF fits over the exposed threaded section and is retained using the corresponding large mounting nut. Secure and correctly tightened hardware is important because this connection is subjected to changing loads during acceleration, deceleration and gear changes.

There are two lower PPF mounting studs fitted per vehicle. This listing supplies one Genuine Mazda stud, so select a quantity of two when replacing both studs.

The stud is supplied with thread-locking compound applied to the differential-housing end. The retaining nut, Power Plant Frame and other mounting hardware are not included.

Replacement should be considered where the original stud is heavily corroded, bent, stretched, cross-threaded, seized into the retaining nut or damaged during differential or PPF removal.

• Part type: Lower Power Plant Frame mounting stud
• Common names: PPF stud / differential-housing stud / differential-to-PPF stud
• Primary use: Secures the differential end of the Power Plant Frame
• Location: Lower section of the rear differential housing
• Quantity fitted per vehicle: 2
• Quantity supplied: 1 stud
• Thread-locking compound: Factory applied
• Retaining nut included: No
• Power Plant Frame included: No
• Brand: Genuine Mazda
• Part No.: 9YA9-0A-401
• Also referenced as: 9YA90A401
• Replaces: 9YA9-01-404B / 9YA901404B
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC models
• Additional application: Mazda RX-8

Fitment advice: This is the lower stud used at the differential end of the Power Plant Frame. It should not be confused with the upper differential carrier studs or the bolts securing the differential carrier to the rear subframe. Confirm the original mounting position before installation.

Other items to consider: Inspect the second lower PPF stud, both retaining nuts, the Power Plant Frame mounting holes, upper differential mounting hardware, differential casing threads and surrounding aluminium components. Replace any fastener with damaged, stretched or heavily corroded threads.

Useful tools / consumables: Suitable socket and spanner set, stud-removal tool or double-nut arrangement, penetrating fluid, calibrated torque wrench, thread-cleaning tools and a suitable transmission or differential support jack.

Difficulty guide: DIY Difficulty: Advanced. The differential and Power Plant Frame must be supported correctly before the mounting hardware is loosened. A seized or broken stud may require controlled heat, drilling or specialist extraction equipment.

Why Genuine Mazda? Genuine Mazda PPF mounting hardware is manufactured to match the original differential-casing thread, stud length, exposed thread and strength specification. Correct dimensions help maintain compatibility with the original Power Plant Frame, retaining nuts and differential housing.

What’s in the box: One Genuine Mazda lower Power Plant Frame-to-differential mounting stud, part number 9YA9-0A-401.

Installation notes: Support the differential and Power Plant Frame safely before removing the original hardware. Clean and inspect the threaded hole in the differential casing without damaging the threads. Install the replacement stud using the factory-applied thread-locking end and tighten it to the depth and specification stated in the applicable Mazda workshop procedure. Position the Power Plant Frame correctly, fit the retaining nuts and tighten the mounting hardware progressively. Confirm the PPF and drivetrain alignment before returning the vehicle to service.