Sliding doors typically operate on rollers that sit on a track. These rollers help the door glide smoothly open and shut. Misalignment can occur for several reasons, including age, repeated use, or an accumulation of dirt and debris. Before you begin adjusting the rollers, it's essential to identify the type of sliding door you have. Most sliding doors will either have adjustable rollers that can be accessed easily or those that may require some disassembly.