How to Replace a Serpentine Belt on a Pontiacby Allen Moore
The Pontiac serpentine drive belt transfers torque from the engine’s crankshaft pulley to the engine accessories in order to power them. The belt rides along the crankshaft pulley and winds its way in a serpentlike manner around all the other pulleys, deflecting off one to reroute toward another. Serpentine systems also have one or two idler pulleys, used strictly to alter the belt path, and a tensioner that holds the belt tightly in place during operation.
Open the hood and locate the serpentine belt routing diagram. The diagram is on a sticker originally adhered to the fan shroud or the underside of the hood for easy referral when replacing the belt. If the sticker is no longer on the Pontiac, you’ll need to get one either from your local Pontiac dealer, in the Pontiac’s specific service manual or online. Or you can draw a diagram of your Pontiac's pulleys and belt, showing how the belt routes around the pulleys.
Insert the tip of the belt tensioner tool into the corresponding notch on the serpentine belt tensioner. You can locate the tensioner by looking for a pulley located at the end of an arm. This arm and pulley assembly is the tensioner.
Pry the tensioner arm away from the belt face with the tensioner tool. On some Pontiacs you can substitute a large socket wrench, but the risk of damage to the tensioner increases greatly with the socket wrench. The price of a tensioner tool is far less than that of a new tensioner, so avoid the socket wrench and buy the proper tool at your local auto parts store.
Push the belt off the tensioner pulley with your free hand and slowly move the tensioner back to its relaxed position. Pull the tool out of the tensioner and set it aside for now.
Pull the belt off all the pulleys and lift it up out of the engine well. Depending on the year, make and model of Pontiac you are working on, you made need to access the lower pulleys from below the engine well or through the wheel well to get the belt out.
Stretch both belts out to full length to make sure the new belt and old belt are nearly identical in length. The new belt should measure less than an inch shorter than the old one. This is due to some stretching the old belt received during its lifespan.
Route the new belt around the pulleys, beginning with the crank pulley and working your way up until the tensioner pulley is the only one left. Make sure to consult the routing diagram frequently during this step. If you route it improperly, you will have to either take it off and start over, replace whatever component this damages from the improper routing, or seek first aid for the injuries you suffer.
Plug the tensioner tool back into the tensioner body and lever the tensioner pulley away from the belt path once more. Pull the belt over the tensioner pulley and hold it there with your other hand as you slowly release pressure on the tensioner. Take the tool out when done.