Chevrolet L Van 1998–1999 — technical service bulletin
Bulletin 990421005 · NHTSA communication 607584 · issued Aug 1, 1999
Technical service bulletin
communication type
Power Train
component
1998–1999
model years
6
vehicle entries
Official summary
Transfer case vibration (shudder) during tight turning maneuvers at vehicle speeds of up to 5 km/h (5 mph) on dry pavement. *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.