How to Replace the Serpentine Belt in a GMC Sierraby Contributor
In the GMC Sierra, a main drive belt or serpentine belt runs multiple accessories. On V6 models, there is frequently one serpentine belt, whereas on a V8 some models have a separate belt for the air conditioning compressor. Most GMC Sierra models have a self-adjusting belt tensioner, making manual adjustment unnecessary. These instructions are based on a limited range of model years for the GMC Sierra from 1999 to 2006.
Find the belt tensioner pulley--generally located above the crankshaft and has a bolt in the middle--and rotate it to release belt tension.
Slip the old serpentine belt off of the tensioner pulley and each of the pulleys it's connected to.
Check the belt routing diagram to find out how to install the new serpentine belt on each pulley. On many GMC Sierra models, the routing diagram can be found on the radiator support. You can also find detailed diagrams and parts descriptions for the GMC Sierra at the Dayco parts site online by selecting the make and model.
Install the new belt. Keeping pressure on the belt tensioner by keeping it released to allow the new belt to fit on. Slip the new serpentine belt onto each pulley including the idler pulley and make sure it is seated in each groove.
Remove the wrench or tool, releasing the belt tensioner so that the belt tensioner can auto-adjust.
Run the engine and observe the belt to check for proper installation.