Technical solutions are described for a clamp mechanism of an adjustable steering column assembly. The clamp mechanism comprises a fixed bracket configured for rigid attachment to a vehicle, and a movable bracket configured to hold a steering shaft. An adjustment nut threadedly engages an adjustment bolt, the adjustment nut or the adjustment bolt moves between an adjustment position and a holding position, selectively coupling the movable bracket to the fixed bracket in the holding position. The fixed bracket defines a first slotted aperture to guide the adjustment bolt in a linear path for adjusting a position of the steering shaft. A positive locking member moves to a locked position, blocking the adjustment bolt from moving along the first slotted aperture in a crash event. A friction plate is pivotably coupled to the fixed bracket to pivot as the positive locking member moves between an unlocked position and the locked position.