The serpentine belt is one of the parts most owners think about only when it squeals. On many cars one belt loops around the alternator, the water pump, the power steering pump, and often the air conditioning compressor. When it wears, the failure can come with little warning, and the question of who checks it, who swaps it, and who keeps the paper tends to get answered at the roadside instead of at your kitchen table. This guide helps you settle that question ahead of time, and it explains what to look for in a service contract so the belt doesn't become a dispute.
Start with the owner's manual
Your owner's manual lists the belt's inspection points and its replacement guidance for your specific engine. That guidance is the reference a shop will quote against and the reference a contract's wear-item wording will usually point back to. Read it before you read anything else. If the manual gives a replacement schedule, write it on the same page as your other maintenance dates so the schedule is visible to you, not just to whoever happens to be looking at the car.
Sort the check from the swap
Looking at a belt is a different job from replacing one. A driveway owner with a flashlight can usually check for cracks, glazing, fraying, missing ribs, and a shiny or hardened surface. Checking tension is harder, and some engines use an automatic tensioner that makes a simple visual test less meaningful. Replacing the belt means routing it around every pulley in the right order, and on some layouts that job also means moving or removing other components. If you are not sure which side of the line your car sits on, that uncertainty is itself the answer: hire the shop.
Decide this in advance, in writing, for each of the three tasks. Who inspects the belt at each service visit? Who replaces it when it fails the inspection? Who confirms the new belt is seated correctly and running true? A simple note in your glovebox folder that names the person or shop for each task will save an argument later.
What a contract may say about the belt
A service contract may treat the belt as a wear item, a maintenance item, or something that falls outside its coverage altogether. These are different outcomes, and they can change who pays for the part and who pays for the labor. Find the wear-item section and the exclusions section and read what each says about belts, pulleys, and tensioners specifically. Do not assume a general statement about wear covers a belt just because the belt wears. Ask the provider to point you to the exact line that answers the question, and get the answer in writing.
Also check whether the contract requires the belt to be inspected or replaced on a schedule and whether it requires you to keep proof that you did. Some contracts ask for the maintenance record as a condition of a claim. If yours does, the record is part of the product, not an afterthought.
Keep the paper
Every belt inspection, replacement, and tension adjustment should leave a written trace: an invoice with the date, the mileage, the part description, and the name of the shop or person who did the work. If you do the driveway check yourself, write down what you looked at and what you found. A short note in a log is enough. The point is that when a claim opens, you can show what was done and when, without relying on memory.
Keep the paper in one folder with the contract, the quote, and the signed page. If you change providers or sell the car, the folder moves with the vehicle, and the next owner or the next provider can see the history.
Questions to ask before you sign
Before you buy any contract, ask the provider these questions and compare the answers word for word with the other providers you are considering. Does the contract treat the belt, its tensioner, and its pulleys as covered parts, wear items, or exclusions? Does it require scheduled belt replacement, and does it ask for proof? If the belt fails between visits, who authorizes the repair, and does the contract require the shop to call the provider first? Does the contract let you use the shop of your choice, or does it limit you to a network? What happens to belt-related claims if the contract is cancelled or transferred?
When you are ready to compare, the published term-by-term comparison on this site lists how the providers we cover handle these lines, and the page on how we score the companies explains what each figure means. Use those pages as a starting point, then confirm the exact wording in the sample contract or the signed form before you rely on it.
Decide before the squeal
The belt will tell you it is failing, usually with a squeal, a chirp, a burning smell, or a warning light. The worst time to decide who does the work is when the car is already on the shoulder. Settle the three tasks now: who inspects, who replaces, and who keeps the record. Put the answers in the folder with the contract. If the answer for any task is that you don't know how to do it safely, hire it out and keep the invoice.