Garage Door Extension Spring w/ Safety Cable 25x42x140 for 7' High Doors 140LB Blue (Sold Each)

• All springs are coated for extended life and rated for a minimum of 10,000 cycles. 
• Double loop ends for longer life.
• Highest quality available.
• DASMA color coded.
• Extension springs require 2 springs to pull the listed weight. Example: it takes two 100lb white springs to lift a 100lb door.
• Made in USA.

1. Raise the garage door to the fully open position. Be sure to disconnect your automatic garage door opener, if you have one.
2. Use C-clamps or vice grips under bottom rollers to keep the door in the open position. With tension completely off extension springs, disconnect springs from track support.
3. Place a bathroom scale under center of door.
4. Remove C-clamps or vice grips and lower door by hand. Lower door slowly by hand onto the scale.  This may require more than one person, doors are very heavy and may crash down if you cannot hold it.
5. Record the weight of the door.
6. If door weight exceeds capacity of the scale, use 2 bathroom scales and use a 2x4 with one end on one scale and the other on a second scale with the door perpendicular to the 2 x 4. Be sure to take into account how much the scale reads with the 2x4 on it and deduct from weight you end up with. Add the weight reading from both scales together to get the total weight of the garage door.

WARNING - Garage door springs, cables, brackets, and other hardware attached to the springs are under very high tension and, if handled improperly, can cause serious injury. Only a qualified professional or a mechanically experienced person should adjust them, but only by carefully following the manufacturer's instructions.