2023 Toyota 4RUNNER

Purchased size 265/70R17 tires (Michelin Defender LTX M/S2) exhibiting severe highway vibration immediately post-installation. The vibration persisted continuously for two years across every rotation, posing serious handling and steering risks. For two years, local shop staff gaslit the customer, claiming an "out-of-round" tire or casing defect was impossible to avoid warranty obligations. During a visit in front of store management, staff repeated the claim in front of management. The customer then presented real-time technical data from Google on the spot, forcing staff to admit casing defects happen. Despite this, management cleared the driver to leave, assuring the vehicle was safe to operate with an infant inside. To obtain objective proof, an authorized TOYOTA dealership inspected the vehicle. The dealer verified steering, suspension, and alignment were completely sound and documented the root cause in writing: "Found front left tire has casing deformation." When escalated to corporate executives—including Robert Moyer and top management—an internal email chain revealed local shop management and corporate leadership actively placing profit over safety, contradicting logs and technical facts to deny warranty coverage. Confronted with dealer documentation and caught in their deceptive paper trail, the company fully refunded all tire replacement and balancing costs. Internal casing deformation is a critical safety hazard; belt/casing failure at highway speeds creates extreme risk of sudden tread separation or blowout. Dealership diagnostic documentation and the deceitful Executive email chain are available upon request. I also have video of shaking while on the freeway with my infant child in the car moments after Costco management assured me we were safe.

Component: Tire – Dunlop Grandtrek AT20 P265/70R17 Vehicle: 2023 Toyota 4Runner (approx. 25,000 miles) After a standard tire rotation, I began experiencing severe steering wheel vibration (flutter) at highway speeds (55–65+ mph) and during braking. The issue started immediately after rotation and has not gone away, even after returning the tires to their original positions. The dealer replaced rotors and pads, but the vibration remained. There are no warning lights, and no visible tire damage. This condition has been reproduced by the dealer. Upon researching, I found that Toyota issued Tech Tip T-TT-0602-20 for this exact issue — citing steering vibration caused by Dunlop Grandtrek AT20 tires on 4Runner models. I also found similar complaints from other owners on forums and the NHTSA database. The issue appears to be related to internal tire defects (e.g., belt separation or out-of-round tires) which are not externally visible. This problem affects safety due to potential loss of steering stability at high speeds, and could worsen over time. Tires have not been replaced yet, but I plan to pursue road force balancing and a manufacturer warranty inspection. I'm glad that I was able to find this problem early before it cause tire explosion. Tire Size: P265/70R17 Tire Brand/Model: Dunlop Grandtrek AT20

The contact owns a 2023 Toyota 4Runner equipped with Falken Tires, Tire Line: WildPeak, Tire Size: 275/70/R17, DOT: (N/A). The contact stated that while driving at an undisclosed speed, the steering wheel and driver's seat began to vibrate violently, prompting the contact to dramatically reduce the speed of the vehicle, but the failure persisted. The vehicle returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the four tires. The independent mechanic found an abnormally heavy spot on all four tires, preventing the tires from being properly balanced. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was opened; however, the manufacturer provided no assistance. The failure mileage was 23,000.

The contact owns a 2023 Toyota 4Runner equipped with Nitto Tires, Tire Line: Ridge Grappler, Tire Size: 265/70/R17, DOT Number: 737079K4222. The contact stated while driving 58 MPH, the steering wheel was vibrating. The vehicle was taken to the dealer, where it was determined that the tires had caused the steering wheel to vibrate. The dealer referred the contact to the tire manufacturer. The vehicle was not repaired. The tire manufacturer was made aware of the failure and a case was opened. The vehicle manufacturer was also made aware of the failure and advised the contact to take the vehicle back to the dealer for assistance from the Service Manager. The failure mileage was approximately 3.