Ive got a 96 Blazer with the 4.3L vortec. Yesterday the engine started making a really terrible sound almost like a airplane propeller. When I was taking a look at the engine it seems that the tensioner pulley has gone bad because it was making the noise and wobbeling alot. Im pretty sure its the tensioner its the pulley between my altenator and a/c compressor. (if its not the tensioner please tell me). Anyways, I'm a broke college student so I cant afford to take it to a shop and have them do it but I've been told that replacing the belt doesnt take that much time. If someone could tell me how to properlly remove the serp. belt and what I need to do to replace the bad pulley (like if i need to use a torque wrench or something) that would be great.

 

There may be a routing diagram on a label on the rad support for your belt, if not, take a picture or make a drawing.
Use a ratchet or a flex bar to remove the tension from the belt.
Slip the belt off the alt pulley, then allow the tensioner to go slack.
Completely remove the belt.
Remove the tensioner mounting bolt and tensioner.
Install the new tensioner.Tighten the tensioner bolt to 37 ft lbs.
Start the belt around the crank pulley and work it in to place, (alt last)
Use your ratchet or flex bar again in the tensioner to move it far enough to install the belt.
remove the tool, check that the belt is properly in all the grooves on all the pulleys and then start the engine.

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