A drive tray assembly is disclosed for placing drives (e.g., hard disk drives) in a computer chassis in a rotated orientation and without the need for additional tools. A tray base holding a drive can be slid into a receiving space of the chassis in a longitudinal direction. An installation lever rotatably attached to the tray base includes a shaft that engages a corresponding receiving slot of the receiving space. After the tray base is inserted, rotation of the installation lever to a closed position causes the tray base, and thus the drive, to move in a direction perpendicular to the longitudinal direction. A release lever rotatably attached to the tray base can secure the installation lever in the closed position until the release lever is rotated, freeing the installation lever to move to the open position in which the drive tray may be removed from the chassis.