# Mainshaft rear bearing C-washer selection clearance (NA6 5MT)

Canonical URL: https://miatatorque.com/spec/mainshaft-rear-bearing-c-washer-clearance-na6-5mt/

Applicability: NA 1990–1993 (B6, 5MT) — 1991–1993 inferred from 1990 factory evidence; actual-year verification is separate.

Confidence: fsm

0–0.1 mm (0–0.004 in)

Always confirm against your factory manual. Match every restriction and follow all stages and procedure notes. Disputed claims must not be automatically resolved. The complete record below preserves every printed unit, source claim and procedure.

```json
{
  "id": "mainshaft-rear-bearing-c-washer-clearance-na6-5mt",
  "name": "Mainshaft rear bearing C-washer selection clearance (NA6 5MT)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NA",
      "years": [
        1990,
        1993
      ],
      "engines": [
        "B6"
      ],
      "trans": [
        "5MT"
      ],
      "note": "1991–1993 inferred from 1990 factory evidence; actual-year verification is separate."
    }
  ],
  "kind": "non-torque",
  "value_text": "0–0.1 mm (0–0.004 in)",
  "procedure": {
    "notes": "After installing the mainshaft rear bearing, C-washers, retaining ring and washer, secure with a new snap ring. Verify no clearance between rear bearing and C-washers. Measure between C-washers and washer, then select proper C-washers to set this clearance. Do not substitute the separate fifth-gear end-play specification."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1990",
      "page": "J–36 (PDF p. 368)",
      "as_printed": "Standard play: 0—0.1mm (0—0.004 in)",
      "verified_years": [
        1990,
        1990
      ],
      "document": {
        "id": "fsm-1990",
        "tier": 1,
        "title": "1990 Mazda MX-5 Miata Workshop Manual",
        "part_number": "1193-10-89C",
        "covers": [
          {
            "gen": "NA",
            "years": [
              1990,
              1990
            ],
            "engines": [
              "B6"
            ]
          }
        ],
        "url": "https://archive.org/details/1990-mazda-mx-5-miata-workshop-manual_202411"
      }
    }
  ],
  "jobs": [],
  "system": "transmission",
  "component": "inventory-pass-2026-10",
  "componentName": "Service measurements and fasteners",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/mainshaft-rear-bearing-c-washer-clearance-na6-5mt/"
}
```