We investigate the combination of Augmented Reality (AR) with Intelligent Tutoring Systems (ITS) to assist with training for manual assembly tasks. Our approach combines AR graphics with adaptive guidance from the ITS to provide a more effective learning experience. We have developed a modular software framework for intelligent AR training systems, and a prototype based on this framework that teaches novice users how to assemble a computer motherboard. An evaluation found that our intelligent AR system improved test scores by 25% and that task performance was 30% faster compared to the same AR training system without intelligent support. We conclude that using intelligent AR tutor can significantly improve learning compared to traditional AR training.