Chevrolet Chevrolet Truck 1998–2003 — technical service bulletin
Bulletin 121202 · NHTSA communication 10002746 · issued Dec 12, 2002
Technical service bulletin
communication type
Power Train
component
1998–2003
model years
12
vehicle entries
Official summary
New transmission oil cooling system flushing tool. 1998 and 2003 chevrolet and gmc medium duty trucks equipped with 4l80e automatic transmissions. *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.