Genuine Mazda Alternator Adjuster Spacer Block Bolt – 1.6
Replacement Genuine Mazda alternator adjuster spacer-block fixing bolt for Mazda MX-5 Mk1 NA models fitted with the 1.6-litre petrol engine.
This flange bolt secures the alternator adjustment spacer block to the alternator mounting bracket. The spacer block forms part of the mechanical adjustment system used to move the alternator and set the correct alternator and water-pump drive-belt tension.
The bolt must hold the spacer block securely while allowing the adjustment mechanism to operate correctly. A seized, damaged or missing fastener can prevent accurate belt adjustment or allow the alternator position to move after installation.
One bolt is fitted per vehicle, and this listing supplies one Genuine Mazda flange bolt. The spacer block, long adjustment bolt and other alternator mounting hardware are supplied separately.
Important fitment restriction: 9079-40-825 fits the alternator adjuster arrangement used on Mk1 NA 1.6 models. Mk1 1.8 and all Mk2/Mk2.5 1.6 and 1.8 models use a different bolt, spacer block and adjustment bolt.
- Part type: Alternator adjuster spacer-block fixing bolt
- Common names: Alternator tensioner-block bolt / adjuster bracket bolt / flange bolt
- Mazda catalogue description: Bolt and washer, flange
- Location: Alternator adjustment spacer block to alternator bracket
- Function: Secures the alternator belt-adjustment spacer block
- Engine application: 1.6-litre petrol engine
- Primary engine code: B6-ZE
- Design: Flange-head bolt with integrated washer face
- Quantity fitted per vehicle: 1
- Quantity supplied: 1 bolt
- Spacer block included: No
- Long adjustment bolt included: No
- Alternator bracket included: No
- Alternator included: No
- Drive belt included: No
- Brand: Genuine Mazda
- Part No.: 9079-40-825
- MX-5 fitment: Mk1 NA 1.6 models
Typical reasons for replacement:
- Bolt seized through corrosion
- Threads damaged or cross-threaded
- Bolt head rounded during removal
- Bolt bent, stretched or fractured
- Original fastener missing
- Spacer block or alternator bracket replacement
- Alternator removal or refurbishment
- Drive-belt tension cannot be retained correctly
Fitment advice: Confirm that the vehicle retains the original Mk1 1.6 alternator mounting and adjustment arrangement. Do not use this fastener for the Mk1 1.8 or Mk2 system unless the complete mounting arrangement has been changed.
Replacement advice: Inspect the spacer block, alternator bracket, long adjustment bolt, lower alternator pivot bolt and all corresponding threads before installation. A new fixing bolt will not correct a cracked bracket or damaged threaded mounting point.
Other items to consider: Inspect the alternator and water-pump drive belt for cracking, glazing, fraying or contamination. Check the alternator bearings, water-pump pulley, crankshaft pulley and surrounding mounting hardware.
Useful tools / consumables: Socket and spanner set, calibrated torque wrench, penetrating fluid, wire brush, thread-cleaning tools and suitable belt-tension measuring equipment.
Difficulty guide: DIY Difficulty: Easy to Moderate. The fastener is relatively accessible, although corrosion or damaged threads may make removal more difficult.
Why Genuine Mazda? Genuine Mazda alternator hardware matches the original thread specification, bolt length, flange dimensions and strength requirements. Correct hardware helps the spacer block remain securely positioned while the drive belt is adjusted.
What’s in the box: One Genuine Mazda alternator adjuster spacer-block flange bolt, part number 9079-40-825.
Installation notes: Disconnect the battery before working around the alternator. Support the alternator and loosen the relevant pivot and adjustment hardware. Remove the original spacer-block bolt and inspect the bracket, block and threaded mounting point. Start the replacement bolt by hand to prevent cross-threading. Reassemble the adjustment mechanism, set the drive belt to the specified tension and tighten the alternator mounting hardware to the applicable Mazda specification. Recheck belt alignment and tension after installation.
| Make | Model | Sub Variant | Chassis / Code | Years | Power (PS) | Engine Codes | Fuel | Transmission | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Mazda | MX-5 | Mk1 NA – 1.6 | NA6C | 1990–1993 | 115 | B6-ZE | Petrol | Manual / Automatic | Alternator adjuster spacer-block fixing bolt; one fitted per vehicle; Mk1 1.8 and Mk2 models use different hardware |
| Vehicle Manufacturer | OEM Reference Number |
|---|---|
| Mazda | 9079-40-825 |