{"nhtsa_id":6091822,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2000-11-15","date":"1999-03-01","document_id":"12590","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN:DRIVELINE:DIFFERENTIAL UNIT","mfr_system":null,"summary":"SOME 4X4 VEHICLES MAY EXHIBIT A MOAN NOISE FROM THE FRONT DIFFERENTIAL WHEN THE VEHICLE IS OPERATING IN 4X2 MODE AND GOES AWAY WHEN OPERATING IN 4X4 MODE. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/6091822","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null},{"id":"differential","name":"Differential","parent":"powertrain"}],"codes":[],"topics":[],"vehicles":[{"make":"FORD","model":"F-150","year_from":1997,"year_to":1999,"match":"exact","vehicle_ids":["1997_ford_f-150","1998_ford_f-150","1999_ford_f-150"]},{"make":"FORD","model":"F-250","year_from":1997,"year_to":1999,"match":"exact","vehicle_ids":["1997_ford_f-250","1998_ford_f-250","1999_ford_f-250"]}],"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":[]}