How to Check and Adjust Car Drive Belts

Most cars today utilize a single drive belt known as a serpentine belt. These belts are normally self adjusting. However, separate drive belts known as V-belts can loosen with age and slip on the pulleys they drive. When this occurs, they must be adjusted to manufacturer specifications.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Socket wrenches
• Wrenches
• Screwdriver
• Pry bar

1. Turn the car engine off and open the hood. Secure the hood with the prop rod.

2. Locate the drive belts. Typically, these are located in the front of the engine and are driven by the crankshaft pulley.

3. Grab the belt with your hand and push it up and down to see how far it moves. There should be no more than 1/2 inch deflection in either direction.

4. Loosen the bolt or nut for the component that the belt drives. Move the component, using a pry bar, to tighten the belt. Recheck the belt deflection as you did before. If the deflection is correct, tighten the bolt or nut on the component.

5. Repeat this procedure for all other drive belts.

Tips & Warnings

• Check how the belts sit on the pulleys. They should not be below the pulley's side walls. If they are, the belts are worn and should be replaced.
• Notice the condition of the belts. Shiny, frayed or cracked belts should be replaced.
• Keep the engine off when checking and adjusting car drive belts. You should never grab a moving belt.