{"nhtsa_id":10027767,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2009-02-03","date":"2008-10-17","document_id":"SB-21-5035","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN","mfr_system":null,"summary":"MACK TRUCK: REVISED FAN HUB MOUNTING BOLT TORQUE. FOR THIS APPLICATION ONLY, THE FAN HUB MOUNTING STUD MATERIAL PROPERTIES AND LENGTH HAVE BEEN CHANGED TO 45MM (WAS 40MM) TO ENSURE FULL NUT ENGAGEMENT. MODEL YEARS UNKNOWN. *PE","document":null,"url":"https://open.wenmarpro.com/bulletins/10027767","components":[{"id":"engine","name":"Engine","parent":null},{"id":"cooling-fan","name":"Cooling fan","parent":"engine"},{"id":"cooling-system","name":"Cooling system","parent":"engine"}],"codes":[],"topics":[],"vehicles":[{"make":"MACK","model":"CHU","year_from":2006,"year_to":2008,"match":null,"vehicle_ids":[]},{"make":"MACK","model":"GU","year_from":2006,"year_to":2009,"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":[]}