See also:

Roof rack system (if equipped)
Loads should never be placed directly on the roof panel. For proper function of the roof rack system, loads must be placed directly on crossbars affixed to the roof rack side rails. Your vehicle m ...

Engine oil
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Second generation (2003–2006)
The Navigator was updated in 2003, along with the Ford Expedition, on the new Ford U platform. The interior was also substantially revised to bring it up to the level expected by luxury buyers. So ...