Ford F-250 SD 2021–2022 — technical service bulletin
Bulletin SSM 50237 · NHTSA communication 10202796 · issued Oct 28, 2021
Technical service bulletin
communication type
Power Train
component
2021–2022
model years
2
vehicle entries
Official summary
Some 2021-2022 F-250 vehicles equipped with a 6.7L engine, 10.5 inch Sterling rear axle with a 3.55 gear ratio (tag S403N), and four-wheel drive (4WD) built on 01-Jun-2021 and through 01-Oct-2021 may exhibit a driveline vibration and/or growl/roar noise between 1700-2100 RPM. Before performing normal diagnostics in the Workshop Manual (WSM), inspect the rear axle to verify if a damper is installed on the pinion flange. If a damper is present, refer to WSM, Section 100-04 for normal diagnostics. If no damper is present, replace the rear axle drive pinion flange using service part number HC3Z-48
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.