How to Replace the Drive Belt on a Porter-Cable Belt Sander
The drive belt is used to connect the motor to the gearbox (which drives the sanding belt on your sander). The rubber belt is a reinforced, cogged type belt. After a lot of use, the belt will begin to deteriorate. The cogs on the belt can wear down (and not provide enough grip), or the belt can become brittle and crack (and break). Sometimes, the belt will fray along the edges, which can potentially damage the sander. If the sander is overloaded, the belt will wear down much more quickly.
Let's get started.
REMOVING THE DRIVE BELT
1. Remove the belt cover.
a. Remove the screws securing the belt cover to the side of the sander.
b. Remove the belt cover from the sander.
2. Remove the drive belt.
a. Insert long-nosed pliers into the slots beside the (center) hex nut on the lower pulley. This will prevent the pulley from rotating during removal.
b. Use a hex wrench to remove the screw securing the lower pulley to the shaft. The hex screw is reverse-threaded (requiring clockwise rotation to loosen).
c. Remove the lower belt pulley and the drive belt from the sander.
INSTALLING THE NEW DRIVE BELT
3. Install the drive belt.
a. Align the new drive belt with the cogs on the upper pulley.
b. Align the belt with the cogs on the lower pulley.
c. Install the lower pulley onto the spindle.
d. Secure the lower pulley with the hex screw. (The screw is reverse-threaded).
REASSEMBLING THE UNIT
4. Reinstall the belt cover.
a. Install the belt cover.
b. Secure the belt cover with the screws.