Genuine Mazda Differential Spacer / Compressor Bracket Flange Bolt • 9979-61-020

Genuine Mazda Differential Spacer / Compressor Bracket Flange Bolt

Replacement Genuine Mazda flange bolt for Mazda MX-5 Mk1 NA and Mk2/Mk2.5 NB models produced from 1990 to 2005.

This fastener has multiple confirmed MX-5 applications. It is used to secure the differential spacer or mounting bracket to the rear differential and is also used in the air-conditioning compressor bracket assembly on applicable vehicles.

At the differential, the bolt is associated with Mazda bracket or spacer reference MA02-27-158. In the engine-bay application, it secures part of the air-conditioning compressor mounting arrangement to the engine.

One Genuine Mazda bolt is supplied per order quantity. The number required depends on the exact installation position and work being undertaken.

Application advice: Because 9979-61-020 is used in more than one location, confirm the original fastener reference and installation position before ordering. The compressor-bracket application is relevant only to vehicles equipped with the corresponding air-conditioning system.

• Part type: Flange bolt
• Common names: Differential bracket bolt / spacer bolt / compressor bracket bolt
• Mazda catalogue description: Bolt, Flange
• Confirmed location 1: Differential spacer or bracket to rear differential
• Confirmed location 2: Air-conditioning compressor bracket to engine
• Associated differential bracket: MA02-27-158
• Quantity supplied: 1 bolt
• Quantity fitted per vehicle: Varies by application
• Differential bracket included: No
• Compressor bracket included: No
• Nut or washer included: No
• Brand: Genuine Mazda
• Part No.: 9979-61-020
• MX-5 fitment: Mk1 NA and Mk2/Mk2.5 NB models

Typical reasons for replacement:

• Original bolt heavily corroded or seized
• Bolt head rounded during removal
• Threads damaged or cross-threaded
• Fastener bent or stretched
• Original bolt missing following previous repairs
• Differential removal or refurbishment
• Differential spacer or bracket replacement
• Air-conditioning compressor or bracket removal

Fitment advice: Confirm the bolt against the removed fastener or applicable Mazda parts diagram. Compatibility with the vehicle does not mean that this bolt is correct for every differential, engine or air-conditioning bracket fixing.

Replacement advice: Inspect the mating threaded hole or nut before installation. A replacement bolt will not correct damaged, corroded or cross-threaded female threads.

Differential application advice: Inspect the associated spacer or mounting bracket, including Mazda reference MA02-27-158, for corrosion, distortion or damaged mounting apertures. Check the surrounding differential mounting hardware while access is available.

Compressor-bracket application advice: Check the air-conditioning compressor bracket for cracking, corrosion or elongated mounting holes. Support the compressor correctly and avoid placing strain on the refrigerant pipes during removal or installation.

Other items to consider: Inspect associated brackets, spacers, nuts, washers and surrounding mounting hardware. Replace any components that could prevent the joint from being tightened securely.

Useful tools / consumables: Suitable socket and spanner set, calibrated torque wrench, penetrating fluid, wire brush and thread-cleaning tools.

Difficulty guide: DIY Difficulty: Moderate. Difficulty varies by position. Differential access requires working beneath the vehicle, while compressor-bracket access may require removal or repositioning of ancillary components.

Why Genuine Mazda? Genuine Mazda mounting hardware matches the original thread specification, shank length, flange profile and material requirements for its catalogue applications. Correct hardware helps maintain the intended clamping force and component alignment.

What’s in the box: One Genuine Mazda flange bolt, part number 9979-61-020.

Installation notes: Support the affected component before removing its mounting hardware. Clean and inspect the mating threads, then start the replacement bolt by hand to avoid cross-threading. Ensure the bolt flange seats flat against the bracket or mounting surface. Tighten it to the Mazda specification applicable to the exact installation position rather than using a generic fastener torque. Confirm that the mounted component is secure and correctly aligned after installation.