The Only Thing More Warped Than a C7 Corvette Wheel is GM's Lackluster Response
GM went with cast aluminum wheels over a stronger forged option for its 7th generation Corvette. Now that owners are having issues with warping and cracking, the automaker is telling them to stop hitting potholes instead of honoring its warranty. Multiple class-action lawsuits have been filed seeking reimbursement for the expensive wheel replacements.
The C7 Corvette (2015-2019) has a widespread problem with cracked and warped rims due to GM's decision to go with cast aluminum over stronger, forged wheels. GM blames owners for hitting potholes instead of offering compensation under their standard 36,000 mile "bumper-to-bumper" (ahem) warranty.
But as complaints rise and lawsuits make their way to court, how long can GM stave off taking responsibility?
Why the C7 Wheels Are Prone to Bending and Cracking ∞
Casting involves pouring molten metal into a mold and letting it cool. It's fine.
Forged wheels are power hammered and pressed until the molecular structure of the casting is changed into something stronger and more resistant. It's often recommended that cars with low-profile tires use forged wheels for the extra strength to protect against everyday damage from potholes and road debris.
But forging takes time and costs money which is likely why GM didn't go that route. But when you're already paying close to $100k for a car, what's a few more bucks to make sure your wheels don't become oblong?
It's possible that GM went with cast aluminum wheels to improve performance. Although I haven't seen much evidence that cast wheels weigh any less than forged wheels.
You know what does weigh less? Using less material than is recommended, which is something GM has been accused of doing to reduce the car's unsprung weight.
Think of unsprung weight as any portion of the car that isn't being supported by the suspension. It's essentially the wheels, brakes, and some random spindles.
Reducing that weight can shave a fraction of a second off lap times. Which might impress your friends, but it won't do much for you when your tires blowout while driving down Main Street.
The combo decision leads to stuttering drivability and dangerous tire blowouts ∞
It's no wonder owners start to experience vibrations while driving like this 2017 Corvette Grand Sport owner with less than 1,000 miles on their car:
Just noticed a vibration in the front end when travel on highway at speed 55+. bring the car to the dealership for inspection and the service manager inform me all 4 wheels has been bend and need to be replace. File a case...with GM customer care center and after 1 week, GM center called and told me this is not cover under the factory warranty. Very disappoint and loosing trust in GM product related to quality, reliability and safety concern for the consumers.
Hundreds of owners have reported their bent or cracked wheel problems to GM, often at low mileage and claims of careful driving.
But the automaker has a boilerplate blame-the-driver response that is deeply troubling considering many claims are made well-within the standard warranty period.
GM is quick to point out that
They offer Tire and Wheel Protection to customers at the time of purchase, which often costs around $1,000 and probably feels like a sucker punch to the gut after spending so much money on a car in the first place.
They point out there are no safety recalls on the 2015-19 Corvettes, nor are there any planned.
Tadge Juechter is one the Corvette's chief engineers and he frequently posts in the Corvette Forum. He said people are surprised that a wheel can be bent without any visible damage, and that a small problem can quickly escalate:
“A frequent sequence of events is that a wheel gets bent by a road hazard but the damage is initially almost undetectable to the driver. Maybe the driver notices a little more vibration, but many times not if the wheel is only slightly out-of-round (just a millimeter or two)."
You can see where this is going.
Owners continue to drive on the ever-so-slightly bent rim which puts additional stress on the thin and damaged rims with every rotation.
"Over time fatigue cracks can form after thousands or even millions of cycles. The wheel doesn’t look any different but begins to leak air at the rim. Since it is hundreds or thousands of miles after the damaging event, the driver often can’t remember hitting anything that would justify a crack in the wheel."
The first lawsuit was filed in early 2019 and claims GM systematically denies coverage despite knowing about the defect.
The lead plaintiff brought their 2018 Corvette into a specialty shop to have the wheels coated, but was informed the wheels were already bent.
The dealership refused to replace the wheels saying the problem was due to how the car had been driven.
Apparently the plaintiff had the wheels repaired for (checks notes) ... $7,500 😱 ... at a 3rd party shop and then contacted GM directly asking for reimbursement. The plaintiff was offered $1,200.
Side note: was he coating the wheels in gold leaf? Holy jeebus.
The plaintiff claims GM is breaching its standard 3 year / 36,000 mile bumper-to-bumper warranty and made a car with wheels that were defective, requiring repair or replacement within the warranty period, and refusing to honor the express warranty by repairing or replacing, free of charge, the wheels.
The lawsuit's breach of express warranty claims dismissed ∞
The plaintiff never provided a plausible claim to his breach of express warranty accusation
The plaintiff didn't allege a defect in the materials or craftsmanship, and the warranty only applies to any vehicle defect, not slight noise, vibrations, or other normal characteristics of the vehicle due to materials or workmanship during the warranty period.
The judge sided with the automaker, saying the warranty requires a customer to go to a Chevrolet dealer facility within the warranty period and request[ed] the needed repairs but the plaintiff used a 3rd party to make the repairs and then asked GM for a reimbursement.
The legal fight is not over as a second consolidated class-action was filed in September 2020 in the Eastern District of Michigan.
The plaintiffs are seeking millions of dollars in reimbursement costs for wheels that are "prone to deforming and cracking without impact damage" because they are "cast rather than forged they are of insufficient strength and insufficient quality to withstand the torque and power output from the drivetrain."
This problem has been reported by owners of the following generations. While there's no guarantee it affects all the listed model years, most years within a generation share the same parts, manufacturing processes, and problems.