NHTSA complaint #11737467

Owner complaint summary

I own a 2022 Acura MDX SH-AWD with approximately 85,000 miles. The issue began suddenly while driving around 5 mph when two loud bangs were heard from the rear drivetrain/transfer case area. After the initial incident, the vehicle was driven home, and the problem became consistently noticeable during any acceleration from a stop or low speed. The drivetrain would clunk/slip during acceleration and exhibited abnormal engagement behavior. Due to concern about causing further drivetrain damage or a potential safety issue, the vehicle was subsequently towed to an Acura dealer for diagnosis. The Acura dealer confirmed that both the transfer case and transmission require replacement due to “worn teeth on splines.” The repair estimate specifically states: “REPLACE TRANSFER CASE AND TRANSMISSION DUE TO WORN TEETH ON SPLINES.” Estimated repair cost is approximately $11,400. I have photographs and repair documentation related to the failure. This failure created a potential safety concern because the drivetrain was no longer operating normally and produced loud clunking/slipping during acceleration from stops and low speeds. A drivetrain or power transfer failure could increase the risk of loss of propulsion or inability to accelerate normally into traffic. The issue was reproduced and confirmed by the Acura dealer. The vehicle has been regularly maintained, including drivetrain fluid services, through Acura/Honda service facilities. There were no warning lights, dashboard messages, or electronic indications before or after the failure event. The only indication was the loud banging noise from the drivetrain/transfer case area and the resulting abnormal drivetrain behavior during acceleration. The service manager also indicated they had seen several similar cases involving this issue.