1999-2005 Standard NB Miata Automatic Transmission Assemblies: Year Branches, Converter, Controls and Listing Contents

No universal supersession or physical-interchange chain is asserted. SB01-19-090C versus SB01-19-090D and SB10-19-090A versus SB10-19-090B are CATALOG_ALTERNATIVES, not proven arrows. SB01, SB10 and SB13 complete-assembly families are YEAR_BRANCHES, not evidence that one family replaces another. TCM, converter, housing, sensors, inhibitor switch, connectors, cooler hardware, shifter and driveshaft are SEPARATE_COMPONENTS. Seller/rebuilder term 03-70LE and recycler numbers 400-60710, 400-61185 and 400-61801 are SEARCH_ALIAS_ONLY or RECYCLER_INTERCHANGE labels; none is a Mazda supersession or permission to cross year branches.

Before ordering, confirm VIN, model year, US/LHD standard naturally aspirated 1.8L build, factory four-speed automatic, emissions/PCM/TCM branch and the exact installed transmission and controller labels; reject a generic '1999-2005' claim. Require photographs of the case/tag, bell/converter housing, pan, extension/output housing, every connector, inhibitor/range switch, sensors, throttle/kickdown lever/cable and cooler ports. Confirm no manual, Mazdaspeed/turbo, NA, NC, non-US/RHD/JDM or swap unit. Itemize the torque converter and whether it is fully retained/installed, flexplate/adapter/bolts, dipstick/fill tube, cooler fittings/pipe/hoses, selector lever/cable/shift-lock actuator/O/D switch, PPF/mount/brackets, output yoke/driveshaft interface, harness, TCM/PCM and hardware; 'complete assembly' does not guarantee any of them. Obtain donor VIN/year, exact assembly identity, mileage, fluid/pan/debris condition, connector/cooler-port damage, leaks/shaft play, actual road/bench test, warranty/return terms, core terms and freight/commercial-address charges. Protect the retained converter and pump during handling and follow current Mazda installation procedures. Diagnose DTCs, power/grounds/wiring, TCM, inhibitor/range switch, speed/revolution sensors, throttle cable, cooler restriction/leaks and fluid level/condition before condemning the gearbox. Clean/verify the radiator cooler and lines and use the exact year-manual/current-service fluid procedure. The checked 2002 manual specifies ATF M-III or equivalent such as Dexron III and approximately 6.7 L total, but final level must follow the dipstick/service procedure and that capacity is not a purchase-quantity promise.

No verified new bolt-in aftermarket complete assembly or broad cross-year interchange is endorsed. Safe choices are an exact-label used Mazda assembly, a professionally remanufactured unit documented to the exact Mazda/year branch, or diagnosis and professional repair of the installed unit. Require a written bill of materials, converter status, cooler/line requirements, calibration/control compatibility, warranty and freight/core terms. A manual swap, JDM/RHD substitution, 03-70LE label alone or internal rebuild recipe is outside this page.

This guide covers only US/LHD 1999-2005 standard naturally aspirated NB factory four-speed automatics. Match VIN, year branch, installed Mazda transmission and controller labels, connector/sensor/cooler/output interfaces and exact listing contents. Early C/D and A/B suffixes are catalog alternatives, not proven supersessions; SB01, SB10 and SB13 year families are not blanket interchange. Converter, shifter/shift-lock, TCM/PCM, cooler hardware, mount/PPF, driveshaft interface and wiring are separate unless itemized. Official Mazda evidence excludes Mazdaspeed/turbo automatics even where seller compatibility tables include them. Diagnose controls, wiring, cooler and fluid faults before buying; verify donor test, condition, warranty, freight and current service procedure.

Supersede reviewed 22 unique research sources for this guide. 7 also appear above as a seller or official action and are not repeated here; 15 additional citations follow.

Research last verified 2026-07-28.

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