Washing machines operate by having a large drum cylinder inside a slightly larger drum cylinder. While washing the clothes are agitated inside the small drum which is perforated to allow water and detergent to enter and leave the inner drum. A thick belt attached to a motor drives the spinning motion of the washer drum. Ideally the belt is nearly taunt and tight to use the motor’s energy efficiently to spin the drum.
However, over time the belt can become too loose and either fall off causing the washer to no longer work or just loosen a little. Unchecked a loose belt can make your washing machine less effective, cause damage, or render the washer unusable until a washing machine belt replacement or repair is done. The washing machine not spinning is a good indication the belt may be loose or broken.
First you must turn off the washer and unplug the power cord. Pull the machine away from the wall to give yourself some ample room. Unscrew the screws on the back panel of the washer. This is also known as the rear access panel. Lift off the panel and you will find the motor and belt assembly.
Find the thick black rubber belt. Tug on it gently to see how much it moves. It should be slightly loose. If it pulls more than a quarter of an inch it is too loose and must be tightened up.
Verify that each end of the belt loop is securely around the pulley system. There will be one connection point on the motor and one on the wheel, gear, or rod that connects to the drum. Depending on the length of the belt there may be other wheels or gears in between that the belt will ride on.
Look for a small nut on the motor right by the point where the washing machine belt meets the motor. Take a wrench and loosen the nut. You will want to turn the nut about half a turn. If you turn too much the nut will fall off and make the belt adjustment more difficult.
Use the back end of the wrench to gently hit the metal mounting plate of the motor. The loosened nut will make the plate movable. Tap it gently until the belt itself tightens. Stop every few taps and gently pull the belt. Once you get the belt to about 1/4 inch of movement in or out you can stop tapping. If you make it too loose, simply tap the mount plate the opposite direction to retighten the belt.
However, if the belt is cracked, excessively worn, or broken you will need a washing machine belt replacement. Pull off the old belt, slip the new washer belt in place (ensure it is in the same position as the old one over the rods and wheels and tighten as needed.
Tighten the mount plate nut back up. Replace the back washer panel and the screws. Carefully move the washer back into position and plug it in. Run the washer a few times to ensure proper operation.
After you've fixed your washer belt, why not take a look at your dryer right next to it. Dryer vent hoses should be checked for kinks and lint build up yearly: How to Remove Dryer Vent Hose Kinks and Lint.