the opener makes a loud grinding or screeching noise right when it starts or stops moving, but the middle of travel is quiet.

Diagnosis

The loud grinding or screeching noise occurring specifically at the start and stop points of the Overhead Door Destiny 1200 is caused by momentary belt slippage or "tooth jumping" on the drive sprocket. When the motor first engages or brakes, it exerts maximum torque on the belt. If the belt has stretched over time or the tension has slackened, the teeth of the reinforced rubber belt fail to grip the metal pulley teeth during these high-torque transitions, causing them to slide and vibrate rapidly against the sprocket. This is often exacerbated by the "soft start/stop" feature of the Destiny 1200, which modulates power. If the belt is marginally loose, the initial surge of power causes a momentary slip (the screech), but once the door gains momentum and reaches a steady state, the centrifugal force and consistent load keep the belt seated, which is why the middle of the travel remains silent. You can confirm this by watching the motor pulley during startup; if you see a slight "shudder" or a momentary jump in the belt before it catches, the tension is insufficient.

How to Fix It

To resolve this, you must recalibrate the belt tension to ensure the teeth are fully seated in the drive sprocket throughout the entire travel cycle.

1. Disconnect the power cord from the ceiling outlet to prevent accidental activation during adjustment.
2. Locate the idler pulley (the tensioning wheel) located at the end of the rail opposite the motor head.
3. Loosen the mounting bolts that secure the idler pulley bracket to the rail using a 7/16" socket wrench.
4. Slide the idler pulley away from the motor head to increase tension on the belt.
5. Perform the "Twist Test": Grasp the belt firmly in the center of the longest span. Attempt to twist the belt. It should resist strongly and should not be able to rotate more than 90 degrees. If it twists easily to 180 degrees, it is still too loose.
6. Tighten the mounting bolts securely, ensuring the pulley remains perfectly aligned with the rail to prevent the belt from rubbing against the side of the bracket.
7. Reconnect power and run the door through three full cycles to ensure the screeching has ceased during the acceleration and deceleration phases.

If That Didn't Work

• Inspect for Belt "Glazing" or Wear: Examine the underside of the belt for smoothed-out teeth or rubber shavings. If the belt has slipped repeatedly, the teeth may be worn down (glazed), meaning no amount of tension will stop the slipping. In this case, replace the drive belt with a genuine Overhead Door replacement part.
• Lubricate the Rail and Rollers: While the noise sounds like the belt, high friction in the garage door rollers can cause the motor to struggle during the initial lift, increasing the torque load on the belt. Use a high-quality lithium or silicone spray on the roller bearings and the track. Never grease the tracks themselves, as this attracts debris.
• Check the Motor Sprocket for Debris: Small pieces of plastic or rubber from a fraying belt can get lodged in the teeth of the drive sprocket. Use a flashlight to inspect the motor pulley; if debris is present, clear it out with a pick or compressed air to ensure the belt teeth can seat fully.
• Verify Door Balance: Disconnect the opener by pulling the emergency release cord. Lift the door manually. If the door slams down or is extremely heavy to lift, the springs are out of balance. An unbalanced door puts excessive strain on the Destiny 1200 motor, forcing the belt to slip under the unnatural weight.

Heads Up

• Avoid Over-Tensioning: Do not tighten the belt to the point where it is rigid like a guitar string. Over-tensioning will put excessive lateral pressure on the motor bearings and the idler pulley, leading to premature motor failure or a snapped belt.
• Avoid WD-40 on the Belt: Never apply lubricants or oils to the drive belt. The belt relies on friction and a specific rubber grip to function; oil will cause the belt to slip permanently and degrade the rubber.
• Check for Rail Sag: Ensure the rail is properly braced to the ceiling. If the rail bows in the middle, it changes the angle of the belt pull, which can cause intermittent slipping at the start and end of the cycle.
• Annual Tension Check: Belt-drive systems naturally stretch over the first 24 months of use. Make it a habit to check the belt tension every autumn before the colder weather causes the rubber to contract and harden.