Chevrolet Silverado 1999–2002 — technical service bulletin
Bulletin 030421004 · NHTSA communication 10002374 · issued May 1, 2003
Technical service bulletin
communication type
Power Train
component
1999–2002
model years
8
vehicle entries
Official summary
Design change of rear output shaft and oil pump replacement parts. *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.