Instead of lubricating the driveshaft itself, focus on these areas for maintenance:
* U-Joint Boots: Inspect the rubber boots surrounding the U-joints for cracks, tears, or damage. If they're damaged, the grease inside can leak out, leading to premature U-joint failure. Damaged boots need to be replaced. This is a job best left to a mechanic unless you have significant automotive experience.
* Driveshaft Support Bearing (if applicable): Some Ford Expeditions have a center support bearing for the driveshaft. This bearing may have a zerk fitting (grease fitting) that requires periodic lubrication, typically according to your owner's manual. Check your manual to see if yours has one and how often it should be greased.
* Overall Driveshaft Condition: Look for any signs of damage to the driveshaft itself, such as bending, rust, or unusual vibrations. If you notice anything amiss, have it inspected by a mechanic.
In short, unless your Expedition's owner's manual specifically calls for lubricating a driveshaft component (like a center support bearing), you shouldn't attempt to lubricate the driveshaft. Focus on inspection and replacement of worn or damaged components.
