Ford F-250 SD 2021 — technical service bulletin
Bulletin 21B03-S4 · NHTSA communication 10198611 · issued Jun 17, 2021
Technical service bulletin
communication type
Power Train
component
2021
model years
5
vehicle entries
Official summary
In all of the affected vehicles, a distressed No. 1 planetary needle bearing inside the ring gear assembly will generate contamination that may produce rough shifts. A wrench light is likely to come on, and the transmission may go into safe mode and only operate in seventh gear. As damage progresses, the transmission may only be capable of limited vehicle speed or may not engage in forward or reverse.
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.