Mechanic Installs 'Triple-Tested' New Alternator From AutoZone. Then He Realizes These Parts Have One Major Issue

"Don't buy anything with a plug from AutoZone."

Mechanic installs ‘Triple-Tested’ new alternator from AutoZone. Then he realizes these parts have one major issue

Photo by: dirty_khaki & Refrina

Stacy Fernandez

By: Stacy Fernandez

Dec 13, 2025 at 8:00am ET

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When you're a mechanic, you count on parts suppliers to deliver a quality product. But sometimes even when parts are allegedly "triple-tested," they fail to meet expectations to everyone’s frustration.

One auto shop's experience with a brand-new AutoZone alternator has reignited a conversation about quality control in the auto parts industry.

In a video with more than 5,900 views, mechanic @dirty_khaki shares a problem that's become all too common at his shop. In the TikTok, he shows what appears to be a brand-new alternator from AutoZone, which claims to be "triple-tested."

But when the mechanic turns the alternator on its side and spins the pulley, it seems loose, even though the customer hasn't dropped it. "Does this happen to you? There is a major quality issue across the board," the mechanic says in the text overlay, adding in the video that they deal with this "all the time."

The mechanic explains that he tries to warn customers about these issues whenever they order parts. But it doesn't seem to help. "You think that's gonna prematurely wear out a belt?" he asks. "Yeah. Sucks."

The video's caption reveals a troubling, though anecdotal, statistic.

"We order brand new parts from local parts-house companies all the time, and they arrive faulty about 20% to 30% of the time. It's quite infuriating," @dirty_khaki writes.

Are Defective Parts Common In the Automotive Industry?

@dirty_khaki isn't alone in his frustration. A Reddit thread in r/Justrolledintotheshop claims this has been a persistent issue. The post, which garnered nearly 400 upvotes, featured a similar video of a brand-new yet purportedly defective AutoZone alternator.

"This has been an issue for decades. I don't know why y'all trust these mf's," one commenter wrote.

Another self-described ASE-certified mechanic chimed in, warning, "Don't buy anything with a plug from AutoZone."

Multiple mechanics shared their own stories. One person who said they’re a shop manager reported going through three alternators and two starters in just six months, all purchased from AutoZone. Another who said they work at O'Reilly Auto Parts described having to warranty out every single alternator since none of them worked.

"Once had to send back every alternator for a certain part # in the whole city," they explained. "Customer returned one he bought, said it didn't work, sure enough, it tested bad. We tested our other new one before he left with it. That one tested bad. Called another store. Both of theirs tested bad."

The consensus among professionals is that remanufactured alternators from major auto parts chains—not just AutoZone, but O'Reilly, Advance Auto Parts, and others—have become notoriously unreliable.

AutoZone's return policy makes it relatively easy to swap out defective parts. Customers can return online purchases to any store or mail them back using the included return form. In-store purchases require the original credit card or receipt.

People who watched the post agreed with the mechanic’s assessment.

"It’s hard to get a good quality part nowadays. It’s BS," one wrote.

"I've been selling parts for 26 years, and quality has become a real issue since COVID. Even at the dealership level," a second said.

What do you think?

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"O'Reilly isn’t any better. I returned 2 calipers the other day where only one side would come out. Junk all around," another wrote.

Motor1 reached out to @dirty_khaki via TikTok direct message and comment and to AutoZone via email. We'll be sure to update this if they respond.

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