“So this is going to be a cautionary tale,” Sherwood Cooke Jr. begins. He’s a trusted Georgia-based shop owner operating two locations down south. The crew at Royalty Auto Service has quite the social media following, since they’re known for their helpful automotive insights. In this one, the tenured mechanic explains how extended warranties sound like a good idea when you’re buying a used car.

However, in his experience, these companies often shamelessly fish for reasons to deny coverage.

Why an expert mechanic hates dealing with extended warranties

The 2019 Nissan Titan rolled into Royalty Auto Service looking like a normal, albeit high-mileage, workhorse. What followed turned into a case study in how extended warranties can unravel fast, even when the owner thinks they did everything right.

Sherwood walked viewers through the 200,000-mile truck’s problem. The complaint sounded messy, but familiar. The key would not turn off. Communication faults popped up. The truck wouldn’t drive. The owner also mentioned earlier shifting problems.

The shop diagnosed the issue as a failed valve body with the transmission control module built into it. On paper, that is a replaceable component. But with that mileage and prior shifting issues, tearing into the transmission for a valve body made little sense. Internal damage was already likely.

To the mechanic, the silver lining seemed obvious

The owner had an extended warranty. He’d purchased it at the dealership when he bought the truck roughly two years earlier, at 121,000 miles.

It was a $3,500 policy from Endurance, financed with the truck purchase. He’d already paid about $2,200 toward it at $113 a month. The truck had not been modified. Maintenance had been done.

Then the denial landed.

According to Sherwood, the warranty company sent an inspector

Photos were taken. VIN verified. And then came the tires.

The Titan was running a slightly different tire size than the factory placard. The variance in circumference was about 0.66 inches. That’s roughly half an inch.

But that was enough.

The claim for a full transmission replacement was denied because the tires were not the original size

They weren’t oversized off-road tires, the mechanic lamented. Not a lift kit, either. They were the exact same tires the truck had when their customer purchased from the dealer.

The mechanic didn’t argue that tire size never matters

Huge tires can stress driveline parts, that’s true, he confirms.

But in this case, the truck was sold that way, warrantied that way, and driven off the lot that way. 

Blaming a half-inch difference for a failed transmission struck the shop as a loophole hunt, not a mechanical conclusion.

The mechanic warns that extended warranties often come with fine print sharp enough to cut later

Buyers need to document everything at purchase. Tires. Wheels. Lift kits. Anything that might be labeled a “modification.” Get answers in writing before signing.

Because once the money is gone, the leverage usually is too.