PCCLOSEOUT

“Lifetime guarantees” are sometimes used in chain stores that do brakes, mufflers, alignments, or transmissions. These are almost always a bad deal for consumers, who pay higher prices for the initial repair with the mistaken belief that they will save money in the long run. But they probably won’t. If the original muffler lasted 80-90,000 miles, the second one will probably last longer than the rest of the car. So why pay extra for a lifetime guarantee? Especially when it might be worthless.
Think about it: Why would a repair shop—that’s in business to make money—want to do a lot of repairs for free? They don’t plan to. They plan on selling additional usually high-priced parts and services to most of the people who come back. And they’re often quick to refuse warranty work to customers who won’t buy additional repairs. They just make up an excuse that sounds good, like: “Your disc pads do have a lifetime guarantee, but they wore out because your calipers and (insert more high-priced parts here) are bad, so I can’t warranty your brakes without first replacing the expensive parts.”
Chain stores frequently use the lifetime guarantee scam to sell additional, unnecessary repairs during the initial service. When shop personnel can’t find any legitimate parts that need replacing, they can always say, “Those parts haven’t failed yet, but we can’t guarantee your brake job without replacing them.” The implication is that it’s not safe to leave those parts on the car, when they might actually work fine for another 4 or 5 years. Of course, they neglect to mention that. This scam is also used on customers who refuse to buy additional parts after being told that the parts are bad.