garage door cable fail-why would it contract

[bsheffer]

So a buddy of mine is a garage door mechanic and sure enough, he appears to have diagnosed a problem whereas my garage door no longer touches the floor on the one side. In the end, the cable on that side(and my door has torsion springs) is failing where it is frayed in several places. He told me that when the cable starts to fray, it contracts which is exactly what I am seeing. I would think it would sort of "lengthen" vs. contract. I am trying to think through why this would happen but am not having any luck??

[daddo]

I would think the energy stored in the "twist" would make it contract when there are fewer cable wires, this leaves an open space for the wires to contract and fill the void when there is little or no tension on the cable.

I say this as in "I'm guessing".

[EricU]

probably getting stiffer through work hardening

[Roly]

Is the cable still wrapped in a single layer on the spool on top ?  With the frays it could easily overlap it self.   Roly

[jteneyck]

What Roly said.

John

[bsheffer]

Looking at the cable, when the door is in the down position, there is only about a full wrap on the spindle at the top and none of the frayed cable is on the spindle.

[jteneyck]

Does the frayed cable overlap itself when the door is in the up position?  If so, that could pull the door out of alignment enough that it stays out of alignment when it's lowered again.  Just a guess.  When my door has gotten out of alignment nothing gets it straightened out again until I take the tension off both sides and start over again.

John

[bsheffer]

yes...it does look like the fray might prohibit the cable from sitting in the grooves completely but very very little and It still seems that once the door goes down, the cable would get taught...

[daddo]

There is one way to find out. Replaced the failing cable. It should be done anyway.

[Mr_Mike]

What's the chance the other cable, for some reason, got longer? Either that, or the spool moved on the shaft.