SL-Series Lock-End Extension Springs for One-Piece Doors

A broken garage door spring is more than inconvenient—it can also be dangerous. The SL-Series Lock-End Extension Springs are designed to work with the E900-R Residential Single-Piece Garage Door Hardware Kit, providing the necessary tension to safely and easily lift your door.

Lock-End springs are most commonly used on wider single-panel (one-piece or California Knee Knocker) garage doors that can accommodate two cars (up to 16 ft. wide). They connect the jamb hardware kit to an anchor point, reducing the manual effort needed to operate the door and preventing potential injury or door damage.

Spring setups vary depending on door size:

• Smaller doors typically use one spring on each side.

• Wider doors may require two springs on each side.

Safety Recommendation: Always replace mounting hardware when replacing springs.

• For single-spring setups, use 97509800 C-Hooks.

• For double-spring setups, use CW15 W-Hooks.

How to Identify Your Spring Size

Each spring is labeled with a part number (e.g., SL728) that breaks down as follows:

• SL = Lock-End spring type

• 7 = Wire gauge (#7 = .177 in. wire)

• 28 = Overall spring length (inches)

Example: SL728 = 28 in. Lock-End Spring, #7 (.177 in) wire

If your spring label is missing, measure the outside diameter and calculate wire size by measuring 10 coils and dividing by 10. Then confirm your spring end style (Lock-End).

Available Part Numbers:

• SL728 – 28" Lock-End Spring (.177 in #7 wire)

• SL730 – 30" Lock-End Spring (.177 in #7 wire)

• SL732 – 32" Lock-End Spring (.177 in #7 wire)

• SLR729C – 29" Lock-End Spring (.177 in #7 wire)

Product Highlights:

• Style: Lock-End extension spring

• Compatibility: E900-R One-Piece Garage Door Hardware Kit

• Cycle Life: Minimum 9,000 cycles

• Single-Spring Setup: Requires 97509800 C-Hook

• Double-Spring Setup: Requires CW15 W-Hook

• Sizing: Determined by part number or measurement method

The SL-Series Lock-End Springs provide safe, durable, and reliable performance for single-panel garage doors—making them the trusted choice for replacements and repairs.