Chevrolet Silverado 2001–2003 — technical service bulletin
Bulletin 030730307A · NHTSA communication 10005580 · issued Nov 1, 2003
Technical service bulletin
communication type
Power Train
component
2001–2003
model years
6
vehicle entries
Official summary
Transmission oil leak, abnormal knocking noise heard at idle. 2500/3500 series pickup models. *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.