Genuine Mazda Power Plant Frame / Power Beam Mounting Nut • 9YB0-4A-401

Genuine Mazda Power Plant Frame / Power Beam Mounting Nut

Replacement Genuine Mazda Power Plant Frame mounting nut for all Mazda MX-5 Mk3, Mk3.5 and Mk3.75 NC models with applicable manual and automatic transmissions.

The Mazda Power Plant Frame, commonly abbreviated to PPF and also described as the power beam or centre bar, forms a rigid structural connection between the gearbox and rear differential.

This flanged mounting nut is used at the Power Plant Frame attachment points on the gearbox and differential assemblies. Correctly secured PPF hardware helps maintain the intended alignment and structural relationship between the engine, transmission and differential.

Eight nuts are used across the complete Power Plant Frame installation. This listing supplies one individual Genuine Mazda nut.

Part-number formatting: Mazda catalogues commonly display the reference as 9YB0-4A-401. The supplied format 9YB04-A401 and compact format 9YB04A401 identify the same component.

• Part type: Power Plant Frame mounting nut
• Common names: PPF nut / power-beam nut / centre-bar nut / gearbox and differential mounting nut
• Mazda catalogue description: Nut / Centre Bar Nut
• Installation area: Transmission and differential mounting structure
• Installation position: Power Plant Frame attachment points at the gearbox and rear differential
• Function: Secures the Power Plant Frame to the transmission and differential assemblies
• Quantity fitted per vehicle: 8
• Quantity supplied: 1 nut
• Power Plant Frame included: No
• Mounting bolts or studs included: No
• Gearbox included: No
• Differential included: No
• Brand: Genuine Mazda
• Mazda catalogue reference: 9YB0-4A-401
• Alternative supplied format: 9YB04-A401
• Compact reference: 9YB04A401
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC
• Additional Mazda application: RX-8

Typical reasons for replacement:

• Power Plant Frame removed during transmission or differential repairs
• Original nut heavily corroded or seized
• Hexagon rounded or damaged during removal
• Threads stripped, damaged or cross-threaded
• Flange or seating face distorted
• Original mounting hardware missing
• Power Plant Frame being replaced
• Gearbox or differential being removed or renewed
• Incorrect general-purpose nut previously installed

Quantity advice: Eight nuts are used across the complete Power Plant Frame installation. This listing supplies one nut; check how many mounting positions are being disturbed before ordering.

Fitment advice: This fastener is used at the Power Plant Frame mounting points around the gearbox and differential. It should not be confused with suspension-subframe, differential-carrier or propshaft mounting nuts used elsewhere beneath the vehicle.

Replacement advice: Inspect all Power Plant Frame mounting hardware whenever the frame is removed or loosened. Do not reuse nuts with damaged threads, distorted flanges or rounded drive faces.

Thread inspection: Check the corresponding mounting bolt or stud before installation. A replacement nut will not repair damaged, stretched or cross-threaded male threads.

Seating inspection: Clean the nut flange and the adjoining Power Plant Frame mounting surface. The flange must sit squarely against the frame or mounting bracket without trapped corrosion, burrs or debris.

Alignment advice: The Power Plant Frame contributes to the alignment of the drivetrain assemblies. Follow the Mazda positioning and tightening procedure whenever the gearbox, differential or PPF has been loosened.

Tightening advice: Support the transmission and differential correctly and tighten the Power Plant Frame fasteners in the specified order. Use the Mazda workshop specification applicable to each mounting position rather than assuming all surrounding fasteners share the same setting.

Other items to inspect: Check the Power Plant Frame for cracking, impact damage or corrosion, together with its mounting bolts or studs, gearbox mounting, differential mounting, propshaft connections and nearby chassis hardware.

Useful tools / consumables: Vehicle lift or axle stands, transmission or differential support, suitable sockets and spanners, breaker bar, penetrating fluid, thread-cleaning equipment and a calibrated torque wrench.

Difficulty guide: DIY Difficulty: Moderate to Advanced. Nut replacement is straightforward where access is available, but loosening the Power Plant Frame may require drivetrain support and subsequent alignment checks.

Why Genuine Mazda? Genuine Mazda Power Plant Frame hardware matches the original thread, flange profile and drivetrain mounting arrangement. Correct hardware is important for maintaining secure attachment and the intended alignment of the gearbox, PPF and differential.

What’s in the box: One Genuine Mazda Power Plant Frame / power-beam mounting nut, part number 9YB0-4A-401.

Installation notes: Raise and support the vehicle safely and support the relevant drivetrain assembly before loosening the Power Plant Frame. Remove the original nut and inspect the corresponding bolt or stud and mounting surface. Start the replacement nut by hand to prevent cross-threading, then position and tighten the PPF according to the Mazda workshop procedure. Confirm that all disturbed gearbox, differential and frame mountings are secure before road use.