# Differential side-bearing preload — bearing-cap pilot span (NB2 and Mazdaspeed)

Canonical URL: https://miatatorque.com/spec/differential-bearing-cap-pilot-span-nb2/

Applicability: NB 2001–2005 (BP-Z3) — Actual 2005 factory evidence; other years in the approved family inferred with owner approval.; NB 2004–2005 (BP-Z3-TURBO) — Actual 2005 shared factory driveline specifications; 2004 MSM inferred with owner approval.

Confidence: fsm

185.428–185.50 mm

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-bearing-cap-pilot-span-nb2",
  "name": "Differential side-bearing preload — bearing-cap pilot span (NB2 and Mazdaspeed)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NB",
      "years": [
        2001,
        2005
      ],
      "engines": [
        "BP-Z3"
      ],
      "note": "Actual 2005 factory evidence; other years in the approved family inferred with owner approval."
    },
    {
      "gen": "NB",
      "years": [
        2004,
        2005
      ],
      "engines": [
        "BP-Z3-TURBO"
      ],
      "note": "Actual 2005 shared factory driveline specifications; 2004 MSM inferred with owner approval."
    }
  ],
  "kind": "non-torque",
  "value_text": "185.428–185.50 mm",
  "procedure": {
    "notes": "Set ring-gear backlash first. Tighten or loosen the adjusting nuts equally until the distance between the pilot sections of the bearing caps is within this range, then recheck backlash and tooth contact. This measured span controls side-bearing preload; it is not cap-bolt torque or a case-spreader setting. Use the correct carrier-specific procedure; the NA6 carrier has a different dimension."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-2005",
      "page": "Differential Assembly Note (PDF p. 1203)",
      "as_printed": "185.428—185.500 mm {7.3003—7.3031 in}",
      "verified_years": [
        2005,
        2005
      ],
      "document": {
        "id": "fsm-2005",
        "tier": 1,
        "title": "2005 Mazda MX-5 Miata Workshop Manual (electronic manual capture)",
        "covers": [
          {
            "gen": "NB",
            "years": [
              2005,
              2005
            ],
            "engines": [
              "BP-Z3"
            ]
          },
          {
            "gen": "NB",
            "years": [
              2005,
              2005
            ],
            "engines": [
              "BP-Z3-TURBO"
            ],
            "trans": [
              "6MT"
            ]
          }
        ]
      }
    }
  ],
  "jobs": [],
  "system": "driveshaft-differential",
  "component": "differential-inspection",
  "componentName": "Differential overhaul inspection and selection",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/differential-bearing-cap-pilot-span-nb2/"
}
```