{"nhtsa_id":634798,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2002-10-09","date":"2002-06-01","document_id":"020601024","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING:ENGINE:GASOLINE","mfr_system":null,"summary":"ON CERTAIN VEHICLES, SUCH AS THE CHEVROLET AND GMC WT 5500 MEDIUM DUTY TILT CAB MODELS, THE ENGINES MAY EXPERIENCE ROCKER ARM DAMAGE OR ROCKER BRIDGE DAMAGE FOLLOWING OVERHAUL OF THE CYLINDER HEAD IF THE VALVE BRIDGE STUD INSTALLED DEPTH IS INCORRECT. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/634798","components":[{"id":"engine","name":"Engine","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"CHEVROLET","model":"KODIAK","year_from":2003,"year_to":2003,"match":null,"vehicle_ids":[]},{"make":"CHEVROLET","model":"T SERIES","year_from":1999,"year_to":2002,"match":"exact","vehicle_ids":["1999_chevrolet_t-series","2000_chevrolet_t-series","2001_chevrolet_t-series","2002_chevrolet_t-series"]},{"make":"GMC","model":"T SERIES","year_from":1999,"year_to":2002,"match":"exact","vehicle_ids":["1999_gmc_t-series","2000_gmc_t-series","2001_gmc_t-series","2002_gmc_t-series"]},{"make":"GMC","model":"TOPKICK","year_from":2003,"year_to":2003,"match":null,"vehicle_ids":[]},{"make":"ISUZU","model":"FRR","year_from":2000,"year_to":2003,"match":"exact","vehicle_ids":["2000_isuzu_frr","2001_isuzu_frr","2002_isuzu_frr","2003_isuzu_frr"]},{"make":"ISUZU","model":"FSR","year_from":1998,"year_to":2002,"match":null,"vehicle_ids":[]},{"make":"ISUZU","model":"FTR","year_from":1998,"year_to":2002,"match":null,"vehicle_ids":[]},{"make":"ISUZU","model":"FVR","year_from":1998,"year_to":2002,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}