The serpentine belt on all GMC Sonoma Pickups controls all of the accessories on the front of the engine. The serpentine belt is one complete belt that has ribs on the inside of the belt. The ribs on the serpentine belt travel inside of the grooves inside of each pulley. Once the serpentine belt starts to crack, it won't be long before it breaks. Make a habit of inspecting the serpentine belt every time you open the bonnet.
Open the bonnet of the GMC Sonoma pickup and find the serpentine belt routing diagram. The belt routing diagram on GMC Sonoma pickup is located on top of the fan shroud. Use the serpentine belt routing diagram for routing the new belt around the pulleys. If you can't find the belt routing diagram, take a notepad and pen and draw out the exact routing diagram of the old serpentine belt around the pulleys.
Find the serpentine belt tensioner on the front of the engine. The belt tensioner on GMC Sonoma pickups is located directly below the alternator. The tensioner has a spring loaded arm on one end and a pulley on the other end.
Insert the 13mm socket onto the bolt head in the centre of the belt tensioner pulley. Turn the belt tensioner counterclockwise with the 3/8-inch drive ratchet to relieve the tension off of the belt.
Slide the serpentine belt out from under the belt tensioner pulley. Release the belt tensioner.
Route the new serpentine belt around the crankshaft pulley on the bottom of the engine first.
Route the serpentine belt around the remaining pulleys by using the serpentine belt routing diagram. Leave the belt tensioner pulley for last.
Turn the belt tensioner counterclockwise. Slide the new serpentine belt around the front of the serpentine belt tensioner pulley. Release the belt tensioner and it will tighten the belt around the pulleys.
Inspect the serpentine belt to make sure that it is seated into the pulleys. Crank the engine and look at the belt again to make sure that it stays seated inside of the pulleys.
Serpentine belt part numbers for GMC Sonoma pickups. 1991 - 1995 GMC Sonoma Gates Multi Rib Belt-W0133-1626465 1994 - 1995 GMC Sonoma Gates Multi Rib Belt-W0133-1834868 1998 - 2000 GMC Sonoma Gates Multi Rib Belt-W0133-1834769 1996 - 2004 GMC Sonoma Gates Multi Rib Belt-W0133-1624643
Always remove the keys from the engine when working inside of the engine compartment in case of accidental cranking.