Some 2020-2021 Explorer/Aviator/Police Interceptor Utility vehicles equipped with AWD may exhibit a binding or shudder sensation while turning and/or while accelerating from low speeds. The concern may also be described as a grinding and/or chatter noise. If the Workshop Manual (WSM) leads to replacement of the rear axle, inspect the differential for damage and differential fluid for metallic chunks in the fluid. Note that some metallic flake in the fluid and/or discoloration is normal and the rear axle should not be replaced for it. If no damage is found to the rear differential, it is not recommended to replace the rear axle assembly. Refer to WSM Symptom Charts (Section 308-07A for 2020 model year; Section 307-07A for 2021 model year) for diagnosis of the transfer case instead.
