Showing specs for all NA & NB Miatas

Mainshaft front bearing to housing shim clearance (NA6 5MT)

0–0.004 in (0–0.1 mm)0–0.1 mm (0–0.004 in)

Factory manualTaken from a Mazda factory workshop manual, with page citation.
Procedure

After pressing the mainshaft front bearing into the bearing housing, measure the bearing-to-housing clearance and select adjustment shims. Printed shim thicknesses: 0.1 mm (0.004 in), 0.15 mm (0.006 in), 0.3 mm (0.012 in).

Applies to
  • NA 1990–1993 (B6, 5MT) — 1991–1993 inferred from 1990 factory evidence; actual-year verification is separate.
  • Verified in: 1990 Mazda MX-5 Miata Workshop Manual