Seeing another post about a garage door has reminded me that my mum and
dad's garage door is knackered. I didn't have time to look at it
properly when I was last there, but I'd like to be prepared for next
time. The main problem is that it doesn't come up properly. It opens
maybe a third of the way, and then you have to heave it up the rest of
the way. Even then, it wants to come back down again. There is a long
thick horizontal spring that twists as the door goes up and down, and
I'm guessing that it has come undone in some way and lost tension. It
doesn't seem to be broken. Can anyone suggest something I can do with
it next time I'm there? Or is it impossible to fix without some kind of
tensioning tool?