While making a left turn from an on-ramp, I heard a loud crunch from the drivetrain and experienced a momentary loss of power. Immediately afterward, the front tires began spinning under acceleration. I realized the vehicle was no longer sending power to the rear wheels and had effectively lost its all-wheel-drive capability. The instrument display continued to indicate that power was being sent to the rear wheels even though the rear wheels were not receiving power. This gave an inaccurate indication of the vehicle’s operating condition. The vehicle was inspected by an authorized Acura dealer. The dealer confirmed that the splines between the transmission and the front power takeoff unit had stripped. The transmission/front differential assembly and power takeoff unit were replaced under warranty at approximately 52,280 miles. The dealer stated that this is a problem they have been seeing on the MDX Type S and also commented on the number of revisions that have been made to the power takeoff unit. The replacement unit installed was part number 29000-61E-070. The failure created a safety concern because it caused a momentary loss of propulsion while turning into traffic, followed by unexpected front-wheel spin and loss of all-wheel drive. There were no warning lights or advance warning before the loud crunch and loss of power. The failed components were replaced by the dealer; whether they remain available for inspection is unknown.

Source: NHTSA complaint ODI #11751644 · view all complaints for this vehicle at nhtsa.gov