# Differential pinion bearing preload (NB1)

Canonical URL: https://miatatorque.com/spec/differential-pinion-bearing-preload-nb1/

Applicability: NB 1999–2000 (BP-4W) — Actual 1999 factory evidence; other years in the approved family inferred with owner approval.

Confidence: fsm

0.9–1.3 N·m {9–14 kgf·cm, 7.9–12.1 in·lbf}

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": "differential-pinion-bearing-preload-nb1",
  "name": "Differential pinion bearing preload (NB1)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NB",
      "years": [
        1999,
        2000
      ],
      "engines": [
        "BP-4W"
      ],
      "note": "Actual 1999 factory evidence; other years in the approved family inferred with owner approval."
    }
  ],
  "kind": "non-torque",
  "value_text": "0.9–1.3 N·m {9–14 kgf·cm, 7.9–12.1 in·lbf}",
  "procedure": {
    "notes": "Rotational resistance of the drive pinion during overhaul, measured without the oil seal. Install a new collapsible spacer, turn the companion flange several turns to seat the bearings, and adjust the locknut while measuring preload. Record the achieved locknut torque, fit the new seal, and follow the full factory reassembly procedure. This is not a fastener tightening torque and is not an in-car seal-replacement tightening instruction."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1999",
      "page": "03–14–10 (PDF p. 365)",
      "as_printed": "Preload\n0.9—1.3 N·m {9—14 kgf·cm, 7.9—12.1 in·lbf}",
      "verified_years": [
        1999,
        1999
      ],
      "document": {
        "id": "fsm-1999",
        "tier": 1,
        "title": "1999 Mazda MX-5 Miata Workshop Manual",
        "covers": [
          {
            "gen": "NB",
            "years": [
              1999,
              2000
            ],
            "engines": [
              "BP-4W"
            ]
          }
        ],
        "url": "https://www.mellens.net/mazda/Mazda-Miata-1999-2001.pdf"
      }
    }
  ],
  "jobs": [],
  "system": "driveshaft-differential",
  "component": "differential-inspection",
  "componentName": "Differential overhaul inspection and selection",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/differential-pinion-bearing-preload-nb1/"
}
```