How to Replace the Idler Pulley on a 1998 Mercury Sable

The idler pulley on a 1998 Mercury Sable is used to maintain belt alignment. The bearings in the pulley are sealed and cannot be greased. If the pulley grinds or squeaks, it should be replaced as the bearings will soon give out. Likewise, if the pulley has a lot of resistance or doesn't turn smoothly, it should also be replaced. The top of the idler pulley is smooth as is the tensioner pulley. When replacing the belt, it is easiest to leave one of the two for last as the belt slides right onto the pulley.

• 1

  Locate the belt routing diagram on the fan shroud or the underside of the engine. If the sticker is missing, sketch out a diagram of the routing so you know how the belt goes on. It can go on several ways, but only one way is the correct way.

• 2

  Fit an appropriate socket onto the tensioner pulley bolt then snap a ratchet into the socket. Push the tensioner away from the engine to relieve tension on the belt. Lift the belt off the pulleys. Move the tensioner back into its original position but do not let it snap back into place.

• 3

  Remove the center bolt from the idler pulley with the appropriate socket. Pull the idler pulley off the engine.

• 4

  Install the new idler pulley on the engine and tighten the bolt firmly. Route the belt around the pulleys, starting at the crankshaft pulley and leaving the tensioner pulley until last. Hold tension on the belt with one hand and with the other hand, slide the socket and ratchet onto the tensioner bolt. Move the tensioner towards the engine.

• 5

  Slide the belt over the tensioner then release the tensioner but do not allow it to snap back into place. Check that the belt is properly aligned on all the pulleys.