A steering column assembly comprising: a support bracket, a telescopic shroud having an outer shroud portion and an inner shroud portion, an end of the inner shroud portion extending into the outer shroud portion, the inner shroud portion being fixed in position relative to the support bracket by a clamp mechanism, an energy absorbing mechanism that includes a puller, a clamp rail fixed to the inner shroud portion including a slot that extends axially along the inner shroud portion, the slot defining two opposing walls which each carry a row of teeth, the two rows thereby being spaced apart from one another with the teeth extending towards each other; the puller being positioned adjacent the slot, a clamp bolt that extends perpendicular to the shroud that may be rotated around its long axis by operation of a locking lever, a toothed block having a row of teeth on each side, the pitch between teeth of each row being equal to, or a whole multiple of, the pitch of the teeth of the corresponding row of the slot, the block being supported by a carrier element that moves in response to rotation of the clamp bolt to move, in turn, the toothed block between a clamped position in which the block is located in the slot with the teeth of the block in the same plane as the teeth of the slot and an unclamped position in which the toothed block is held such that the teeth of the block are out of the plane of the teeth of the slot, the block being releasable from the carrier element in the event of a crash such that the toothed block contacts the puller, and in which a contact face of the puller and a contact face of the toothed block are arranged such that the toothed block is prevented from rotating more than a predetermined amount when forced onto the puller, urging the toothed block into engagement with the teeth of the slot. a support bracket, a telescopic shroud having an outer shroud portion and an inner shroud portion, an end of the inner shroud portion extending into the outer shroud portion, the inner shroud portion being fixed in position relative to the support bracket by a clamp mechanism, an energy absorbing mechanism that includes a puller, a clamp rail fixed to the inner shroud portion including a slot that extends axially along the inner shroud portion, the slot defining two opposing walls which each carry a row of teeth, the two rows thereby being spaced apart from one another with the teeth extending towards each other; the puller being positioned adjacent the slot, a clamp bolt that extends perpendicular to the shroud that may be rotated around its long axis by operation of a locking lever, a toothed block having a row of teeth on each side, the pitch between teeth of each row being equal to, or a whole multiple of, the pitch of the teeth of the corresponding row of the slot, the block being supported by a carrier element that moves in response to rotation of the clamp bolt to move, in turn, the toothed block between a clamped position in which the block is located in the slot with the teeth of the block in the same plane as the teeth of the slot and an unclamped position in which the toothed block is held such that the teeth of the block are out of the plane of the teeth of the slot, the block being releasable from the carrier element in the event of a crash such that the toothed block contacts the puller, and in which a contact face of the puller and a contact face of the toothed block are arranged such that the toothed block is prevented from rotating more than a predetermined amount when forced onto the puller, urging the toothed block into engagement with the teeth of the slot.