DIY guide · Moderate
How to replace a serpentine belt
One belt runs the alternator, power steering, A/C and often the water pump. When it cracks or squeals it is time to replace it, and the job is mostly about routing the new belt correctly.
- Difficulty
- Moderate
- Time in the bay
- 1 to 2.5 hours
- Best bay
- Floor bay
- Bay cost, plus tax
- $40 to $50
This is a general guide, not a manual for your car. Your vehicle's service manual comes first, especially for torque values, fluid types and capacities. Support the car on the lift locks or jack stands before you go under it, wear eye protection, and if a step feels wrong, stop and ask us. We do not do welding, grinding or painting in the bays.
Look these up before you book
- The belt routing diagram
- Which way the tensioner moves
- Whether your car needs a special tool or has no accessible tensioner
Tools
- Breaker bar or serpentine belt tool
- Sockets
- Flashlight
- Phone to photograph the routing
Parts and fluids
- Serpentine belt
- Tensioner and idler pulleys if they are noisy or loose
There is an AutoZone nearby, and during business hours parts usually reach the shop in about 10 to 20 minutes. Forgot a filter or need a different size? Order it, keep working, and do not lose your slot.
The retailer's own vehicle picker confirms what fits your car. Always compare the part number with your old part.
Step by step
- Photograph the routingA clear picture of the belt path saves time. Many cars also have a diagram on a sticker.
- Release the tensionerFit the tool on the tensioner and rotate it until the belt goes slack, then slip the belt off a pulley.
- Inspect the pulleys and tensionerSpin each pulley by hand. Roughness, wobble or noise means replace it.
- Route the new beltFollow your photo. Leave the last pulley easy to reach, usually a smooth one.
- Check the seatingRelease the tensioner slowly and confirm the belt sits fully in every groove.
- Start the engineListen for squeal and check the belt tracks straight.
Mistakes to avoid
- Skipping the routing photo
- Leaving the belt off one rib of a pulley
- Replacing the belt without checking a noisy tensioner
- Letting the tool slip when the tensioner releases
Stop and ask for help if
- If the belt shreds and wraps around a pulley or the engine overheated, check the water pump and cooling before restart.
Doing it in our bays
Many engines are reached from above, so the floor bay is enough. If yours is easier from underneath, use a lift.
Every bay has air, power, work lights and jack stands, and the lift bays come with a short safety walkthrough. Bring your own hand tools, parts and fluids. New to lifts? Read how your first visit goes.
Questions
How do I know it is worn?
Look for cracks across the ribs, missing chunks, glazing and a squeal on start or turn.