Chevrolet Sierra 1999 — technical service bulletin
Bulletin 990309003 · NHTSA communication 6088678 · issued Oct 1, 1999
Technical service bulletin
communication type
Suspension
component
1999
model years
6
vehicle entries
Official summary
Vehicles with 4l60-e automatic transmissions may exhibit vibration during acceleration from 0 - 40 km/h (0-25 mph). *tt
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.