Q: What is the purpose of the clutch pilot bearing and how should it be inspected and replaced on Mercury Cougar?
A: The clutch pilot bearing is a needle roller type bearing which is pressed into the rear of the crankshaft. The pilot bearing incorporates an O-ring seal which can't be replaced separately - if there is any evidence that the seal has been leaking, or if the bearing is dry, replace it. It is greased at the factory and does not require additional lubrication. Its primary purpose is to support the front of the transmission input shaft. The pilot bearing should be inspected whenever the clutch components are removed from the engine. Due to its inaccessibility, if you are in doubt as to its condition, replace it with a new one. Remove the transmission. Remove the clutch components. Inspect for any excessive wear, scoring, lack of grease, dryness or obvious damage. If any of these conditions are noted, the bearing should be replaced. A flashlight will be helpful to direct light into the recess. Removal can be accomplished with a special puller and slide hammer, but an alternative method also works very well. Find a solid steel bar which is slightly smaller in diameter than the bearing. Alternatives to a solid bar would be a wood dowel or a socket with a bolt fixed in place to make it solid. Check the bar for fit - it should just slip into the bearing with very little clearance. Pack the bearing and the area behind it (in the crankshaft recess) with heavy grease. Pack it tightly to eliminate as much air as possible. Insert the bar into the bearing bore and strike the bar sharply with a hammer which will force the grease to the back side of the bearing and push it out. Remove the bearing and clean all grease from the crankshaft recess. To install the new bearing, lightly lubricate the outside surface with lithium-based grease, then drive it into the recess with a soft-face hammer. The seal must face out. Install the clutch components, transmission and all other components removed previously, tightening all fasteners properly.