Plug-End - P-Style Extension Spring For One-Piece Garage Doors

When a spring fails on an E900-R one-piece garage door—commonly known as a California Knee Knocker—it creates a significant safety hazard. North Shore Commercial Door offers a complete selection of Plug-End Extension Springs to restore safe, reliable door operation.

These Plug-End style springs are specially designed for single-panel garage doors using the E900-R hardware kit, mounting on each side of the door to assist with lifting. They are rated for a minimum of 9,000 cycles, delivering consistent force and ease of use. Each spring features a unique plug-style end and comes in a variety of lengths and wire gauges.

For proper function, make sure to purchase replacement hooks (sold separately).

• Single spring per side: Use 97509800 C-Hooks

• Two springs per side: Use CW15 W-Hooks

How to Identify the Right Spring

If your spring has a label, the part number gives you everything you need:
Example: P928 → Plug-End (.148" wire, 28" long)

• P = Plug-End

• 9 = 9-gauge wire (.148")

• 28 = 28 inches length

If your spring doesn’t have a label:

1. Measure the outside diameter across the coil

2. Measure 10 coils, then divide by 10 to get the wire size

3. Visually inspect and match the end style

Available Models:

• P728 – 28" Plug-End Spring (.177" #7 wire)

• P728L – 28" Low Tension Plug-End Spring (.177" #7 wire)

• P730 – 30" Plug-End Spring (.177" #7 wire)

• P528 – 28" Plug-End Spring (.207" #5 wire)

• P928 – 28" Plug-End Spring (.148" 9-gauge wire)

• P732 – 32" Plug-End Spring (.177" #7 wire)

• P328 – 28" Plug-End Spring (.244" #3 wire)

Product Highlights:

• Designed for use with E900-R Single-Panel Garage Door Hardware Kit

• Plug-End design for secure mounting

• Available in multiple wire sizes and lengths

• Rated for 9,000 cycles minimum

• Sold individually—hooks sold separately

• Replacement spring guide included in product instructions