Chevrolet Silverado 1999 — technical service bulletin
Bulletin 99027 · NHTSA communication 608377 · issued Aug 1, 1999
Technical service bulletin
communication type
Power Train
component
1999
model years
3
vehicle entries
Official summary
General motors has decided that some vehicles equipped with 4.8l or 5.3l engines and 4l60-e automatic transmissions, and vehicles equipped with 3.73 rear axles and ordered with the heavy-duty trailering package may not have included the merchandising-intent auxiliary transmission oil cooler. *tt
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.