How to Replace Pulley Bearing on Alternator

Replacing a pulley bearing on 90 percent of alternators is a fairly benign task, the hardest part typically being the removal of the alternator. 

Some vehicles feature the alternator on top of the engine, and hence relatively easy to remove. 

On other models, the alternator is on the bottom of the pulley system for the drive belt, in which case you must lift the vehicle.

 A Haynes repair manual for your specific vehicle will guide you through the alternator-removal process. In many applications, to replace the pulley will require the removal of the alternator.

How to replace Step by Step

Step 1

Place a suitable sized 1/2-inch drive impact socket onto the alternator pulley bearing retaining nut.

Step 2

Test the gun to make sure it is rotating counterclockwise.

Step 3

Attach the anvil of the gun to the square drive of the socket.

Step 4

Use a pair of channel locks to hold the pulley bearing stationary.

Step 5

Remove the pulley bearing.

Step 6

Insert the new pulley bearing in the alternator. Replace the washer and the pulley bearing retaining nut. Hand-thread the nut on.

Snug the nut with the impact gun, but do not over-tighten it. Tighten the pulley bearing retaining nut to the correct torque specifications for the specific alternator you're working on.