Allister, Allstar & Raynor Sprockets - DDM Garage Doors

The old Allister and Allstar openers use two black sprockets. The one above the motorhead moves to activate the limit switches as the limit dogs reach their shut-off points.

An Allstar Model 6500 Garage door opener
Allstar Model 6500 Garage Door Opener

The one above the garage door acts as an idler. Raynor also used similar black sprockets just for idlers above the door.

horizontal black sprocket with a black chain wound around it
Allister Black Idler Sprocket Pictured Above the Garage Door

Over the years the chains stretch and loosen. As a result, the pitch of the chain breaks the teeth on the sprocket. In order to prevent this problem, Allstar stopped producing the black sprockets and replaced them with black pulleys.

Another Allstar black sprocket at the end of the opener rail
Allstar Black Idler Pulley at the End of the Opener Rail Above the Garage Door

In 2021 Allstar quit selling parts for their openers, so now we carry a white idler pulley that has a similar shape as the black pulley. The outside diameter is 2 1/2 inches, and the bolt hole for securing the pulley to the end bracket is 1/2 inch. These pulleys don’t break when the chain loosens.

The round box for replacement idler pulleys
Replacement Idler Pulley for Allister and Raynor Sprockets

If the sprocket above the door breaks, you can replace the black sprocket with the pulley. However, if the sprocket above the motorhead breaks, you will need to get a new opener. Those sprockets are no longer available.