On Mon, 26 Nov 2012 09:47:05 -0600, Doug wrote:

Hypothetically, on a metal garage door, if the torsion spring breaks,
can you disengage the garage door from the garage door opener (track)
and open and close it?

Suppose there are 2 torsion springs and only one spring breaks,
same question?

Hi Doug,

Q: Can you disengage the garage door from the GDO with a broken spring?
A: Yes. There is no relationship to the spring whatsoever for disengaging.

Q: Can you then open & close the door manually (with a broken spring)?
A: Yes. But.

The torsion spring was counterbalancing the door - so - now YOU need
to lift the weight of the door which 'was' handled by the broken
spring. My single-car door is 127 pounds. A double-car door can easily
be double that.

BTW, "closing" the door will be easy (gravity does the work for you).
But think about how you would go about 'stopping' two to four 50-pound
bags of cement falling 7 feet along the tracks.

Q: If one of two torsion springs break, can you manually open the door?
A: The answer is the same. The only difference is that half the weight
of the door is on you, the other half is on the matched unbroken spring.

There are two (and only two) web pages you need to fully understand
garage door torsion springs. I've read dozens, and I've watched every
youtube video out there - but you only need these two pages:

1. Richard Kinch (background material)
2. Dan Musick (DDM Garage Doors DIY info)