Oven racks will stick if they are dirty or have been left in a self-cleaning oven during the cleaning cycle. Even the smallest amount of burnt-on grime can interfere with their movement. Rotating the oven racks will help keep them in shape and counteract their tendency to bend after years of use. Lubricating with oven-safe oil is another option to make oven racks slide.
Make the Racks Slide
Take the oven racks out when using the oven's self-cleaning cycle. The intense heat can warp the racks, which will cause them to stick.
Clean the oven when the racks will not slide easily. Grime and grease builds up on their tracks, obstructing the sliding motion. Oven cleaner is made to break down the buildup in the oven but should be used only if your oven is not self-cleaning. Even if it is, you should periodically run a cloth dampened with soapy water along the tracks to clean them.
Soak the racks overnight in a bathtub filled with hot sudsy water. Use laundry detergent with a degreaser to get rid of the baked-on grime. In the morning, the racks will be sparkling like new.
Rub peanut oil on the edges of the oven racks that contact the tracks. Peanut oil has a high burning capacity and will not smoke under normal oven heat as other oils will. You can also use cooking oil spray as a lubricant, but it may smoke when the oven is turned on.
Change the position of your oven racks, putting the top one on the bottom and the bottom one on the top. Sometimes oven racks can be just a fraction off because one ends up holding heavier loads. Rotating them once a month will keep them in more uniform shape.
Purchase an oven-rack gripper from your local kitchen store. It is a hand-held tool that allows you to pull the rack out at just the right angle. They may stick if pulled in too much of an upward direction.