How To Check Serpentine Belt Alignment On An LS Engine

Accessories drives are a crucial part of an engine assembly. The belt or belts keep critical components like the water pump, alternator, and power steering operational. From our experience, if a belt is misaligned, that is when the problems start. This small dilemma can lead to disaster if not taken care of properly. While this issue was more common with v-belts of the past, it can still be a matter with a more modern serpentine belt system. But, making the correct adjustments to a serpentine system is not an easy task.

If you do an LS-swap and change anything out on the accessory drive, it’s a good idea to check the alignment. Some signs of improper belt alignment include squealing, fraying, and even belt failure. While adjusting pulleys is easy enough on an LS, knowing which way to go is not as straightforward. Luckily, Coverman66 has a YouTube video about a handy little tool that will cure those crooked belt problems.

In the video, Terry uses a Dayco Belt Diagnostic Kit (PN 93874) to get the correct alignment. What we found interesting about this tool is that one, we didn’t know it existed and two how easy it is to use. The main part of this tool is a laser pinter with a magnet. The pointer will attach to the crank pulley. You will then put the second part of the device on a different pulley, like the power steering pump or alternator. With the laser turned on, you will then rotate the accessory until the laser shows up on the marker. This marker will allow you to see if the pulley is inline or needs to be adjusted in or out. You will then repeat this process with all of your pulleys to ensure everything lines up.

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Brian Havins

A gearhead for life, Brian is obsessed with all things fast. Banging gears, turning wrenches, and praying while spraying are just a few of his favorite things.
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