Chevrolet Impala 2004–2005 — technical service bulletin
Bulletin 3367 · NHTSA communication 10014908 · issued May 11, 2005
Technical service bulletin
communication type
Power Train
component
2004–2005
model years
2
vehicle entries
Official summary
3-2 downshift buzz noise on 2004 and 2005 police impalas equipped with the 3800 v6 engine and the 4t65e transmission. *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.