← Mazda Miata NB (1999-2005 US model years)
Will 1994-2005 differential, driveshaft and axles (7-inch rear) fit a Mazda Miata NB (1999-2005 US model years)?
Short answer: Yes. Confirmed
Yes: 1994-2005 1.8 rear ends (open or Torsen/LSD) interchange on an NB without changing axles or driveshaft, except Mazdaspeed units.
| Part | 1994-2005 differential, driveshaft and axles (7-inch rear) |
|---|---|
| Vehicle | Mazda Miata NB (1999-2005 US model years) |
| Years | 1999-2005 |
| Trim / condition | non-Mazdaspeed 1.8 rear ends |
| Verdict | Reported to fit |
| Confidence | 3 of 3 — Backed by a manufacturer document, or two or more independent sources agree on a specific checkable fact. |
| Last verified | 2026-10-20 (date the cited sources were last read) |
Details
1994-2005 1.8 rear ends (open or Torsen/LSD) interchange on an NB without changing axles or driveshaft, except Mazdaspeed units. Watch the ratio: NA8 4.1, NB 5-speed 4.3, US 6-speed 3.909, 2004-05 6-speed 4.10. Swapping only the LSD 'pumpkin' into your housing needs resealing; swapping a complete rear is simpler.
Specs
- ring gear in: 7
Related known issues
Related build entries
Other drivetrain fitment for the NB
- NB 6-speed manual transmission (with NB shifter) — Reported to fit
- 2004-05 Mazdaspeed Miata Torsen differential with MSM axles — Fits with extra parts or work
This part on other generations
- Mazda Miata NA (1990-1997) — Fits with extra parts or work
Sources
- NB Diff in NA?? — MX-5 Miata Forum (forum thread; read 2026-10-20; search excerpt only)
- The differential in NB, are they all the same? — MX-5 Miata Forum (forum thread; read 2026-10-20; search excerpt only)
- Miata Torsen Differential Buyer's Guide — Redline Auto Parts (used-parts dealer) (vendor article; read 2026-10-20; search excerpt only)
Summaries are in our own words. Fitment is not guaranteed — disclaimer.
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