RepairPal Certified shops can diagnose and repair your 1999 Oldsmobile Bravada. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
It sounds like you may have a problem with the awd system in your 1999 Oldsmobile Bravada. There is a GM service bulletin to address this issue, #99-04-21-005E.