NHTSA Service Bulletin 11033160: 2019-2025 Freightliner Sprinter (Vs30)

Sprinter 907 - Rear Axle Noise Diagnosis Best Practices Complaint Various noises from area of rear axle while driving Cause A: Howling Noises The highfrequency howling noise is caused by the normal meshing behavior of the rear axle gear set, consisting of the pinion and crown gear. Two example noise recordings are provided in the attachment for reference. The volume and perception of this noise can vary depending on vehicle weight and load condition. Due to the current design of the Sprinter rear axle, it is not possible to completely isolate or decouple the the vibration generated by the normal meshing of the rear axle gears from the vehicle body. As a result, this noise may be transmitted into the vehicle interior. This noise is considered a normal characteristic of the rear axle design and vehicle operation. As it is not the result of a technical failure, component repairs or replacements will not lead to an improvement. There is no negative impact on the function, durability, service life, or operational safety of the rear axle. B: Other Noises: Noises that differ from the described howling characteristic (for example grinding, droning, or chattering noises) are not considered normal and may indicate a technical concern. Possible causes may include, but are not limited to: Damaged bearings Increased or abnormal gear wear Excessive play within the differential Remedy Remedy for Cause A: Do not replace any components. This noise is considered a normal characteristic of the rear axle design and vehicle operation. Remedy for Cause B: If the noise does not match the described howling characteristic, the concern must be diagnosed and documented using the guidance below, with the results included in the warranty claim as applicable. Documentation of Concern: In many cases, the concern can be remedied using available replacement parts, and a complete rear axle assembly replacement is not necessary. However, due to parts availability, tool availability and workshop constraints, a complete assembly replacement may be performed in select cases to mitigate vehicle downtime. IMPORTANT: This is not intended to be the default repair approach. Component replacement must not be performed without diagnostic findings that clearly support a technical defect. Replacing rear axle components without confirmed abnormal findings may result in a debit of the warranty claim. This document does not guarantee warranty coverage and is designed to aid in diagnosis and subsequent resolution of the complaint. Create a file with all of your documents, findings, photos and sound files. 1. To ensure there is a clear understanding of the customer complaint, collect and document the following information: - When did the noise start? - Verify whether any previous repairs or work were performed prior to the onset of the noise. - Did the noise occur suddenly, or did it develop progressively over time? - Is the vehicle upfitted, modified, or retrofitted? (List all modifications) - Attach photos of any modifications or added equipment. - Under which conditions does the noise occur? (Provide all that apply) Vehicle speed Selected gear Load condition Outside ambient temperature and/or weather conditions Engine and drivetrain temperature Diagnosis and Inspection: 2. Collect a video or sound file of the noise concern, ensure the video is available if requested. 3. Perform an NVH recording and store the .pp data file. The file must be available if requested during warranty review or parts inspection.