If a matching pair is no longer offered for your door weight, convert to a single spring configuration. The most reliable approach is upgrading to TorqueMaster Plus with a complete conversion kit that includes springs, a winding assembly, and cable drums.
Select the Complete Plus Upgrade option on the product page to get all required parts with your spring replacement: Order the Complete Plus Upgrade kit.
Double to single on Original style: remove the left spring and gears on the left bracket, then reuse the left winding cone as a spacer to support the left side assembly. Confirm drum orientation and cable routing before winding.
Single to double or any upgrade to Plus: order the Complete Plus Upgrade. Mixing partial components leads to fit and winding issues.