2022–2023 Acura MDX Spline Failure — NHTSA Update & Potential Class Action

For those following the transmission/transfer case (PTU) spline failures on 2022–2023 Acura MDXs, there are some important updates.

NHTSA recently completed its review and acknowledged reports of the splines between the transmission and PTU becoming damaged/stripped, resulting in loss of power to the rear wheels. NHTSA also noted that the SH-AWD display may continue showing rear-wheel torque even after the mechanical connection has failed.
NHTSA ultimately declined to open a formal safety-defect investigation because it determined there wasn’t sufficient evidence of an unreasonable safety risk, since the vehicle can continue operating using the front wheels. This does not mean NHTSA determined the spline failures aren’t occurring.

There is also now a potential class-action investigation specifically involving this issue in 2022–2023 MDXs.

Chimicles Schwartz Kriner & Donaldson-Smith (CSKD) is asking affected owners to submit their experiences here:
https://chimicles.com/acura-awd-failure-transfer-case-investigation/

If you’ve experienced this failure, especially if you paid out of pocket for a transmission/transfer-case replacement, consider submitting your information and keep your dealer diagnosis, repair invoices, mileage, and any correspondence with Acura.

You should also file a NHTSA complaint if you haven’t already:
https://www.nhtsa.gov/report-a-safety-problem