How to Replace Serpentine Belt Tensioner and Pulley 2003-06 GMC Yukon

Remove the negative terminal from the battery. Just use a 8-millimeter wrench and just slide that out of the way. Take this cover off. Just use a 8-millimeter socket. Remove this bolt. Just pull the cover up and slide forward. Loosen up this one clamp right here. Use a straight blade screwdriver. Loosen this clamp as well. Take this hose bracket off of the intake. Just use a trim tool. Pop this off, just like that. Grab it right here, just rock it back and forth, sliding it forward. And also right here. Pop it off and pull it up.

Now, you're going to use a serpentine belt tool. We're going to use the 15-millimeter adapter on the end of it. If you don't have one, you can just use a 15-millimeter wrench. Just be careful. Loosen up the tension on it as if you're turning it clockwise. And then over on the idler, just take the belt off. Release the tensioner. Pull off your tool. Now, just take the belt off. I'm just going to take it off the harmonic balancer or the crank pulley, slide it off the tensioner. Slide it over the water pump, just to keep it out the way. If you're just doing the AC belt down below, you can just leave the belt off at this point, you wouldn't have to take it off all the way. If you're replacing it, take it off the alternator, off the power steering pump, and the idler pulley.

Now, we'll take the tensioner off. Use a 15-millimeter socket. There's three bolts in the front. Now, the bottom one's a shorter one, and the top two ones are longer. And be careful with the fan. You don't want to crack the fan if you're using a air ratchet or an electric ratchet. And pull that out. To take the idler pulley off, I'm going to use a 15-millimeter socket. And slide it out. Take the new tensioner pulley. Get the bolt started. Now, we can torque these to 37 foot-pounds. Take the new idler, get it in position and then tighten it up. Now, we'll torque this bolt to 37 foot-pounds.

All right, take the serpentine belt, and then go around the crank pulley down below, and then come up. Take one side of the belt, just go over the tensioner pulley. The other side goes on the backside, goes over the water pump, and then you're going to go down around the power steering pump pulley, and then up to the alternator. Take your belt tensioner tool. Carefully, while you're holding the belt near the idler pulley over here, take the tension off of the tool, the tensioner, and slide it under the idler. Just double-check. Make sure the belt is over all the pulleys. It looks good. Take the tool off. Should be good.

Now take the snorkel, line it up. Put it on the throttle body. And then over here on the airbox or over the mass airflow sensor, hook this holder on, just like that. A straight blade screwdriver, tighten up the worm clamp. Snug that up, and tighten this one up. Very good. Slide the cover in position, and tighten down the bolt. Take the negative terminal, connect it to the battery. Use a 8-millimeter wrench and tighten it up. Just make sure it's not...won't wiggle loose. Looks good.