Finally figured out why everyone's door hanger cables keep snapping on MRL jobs

I've been replacing these things for 3 years now (in the Denver market mostly) and I kept seeing the same failure point right where the cable passes through the top sheave. Took me until last week to realize the guys on my crew were running the cables with a twist in them. Like they'd unspool them and just let them spin. That tiny twist puts a weird torsion on the cable when the car travels and over time it fatigues the strands right at the pinch point. I tested it by marking a cable straight off the spool (no twist) on a 12-stop job and it lasted 14 months before any fraying showed up. The old ones were failing at 6-8 months. Has anyone else noticed this or am I just late to the party on something obvious?

2 comments

2 Comments

the_julia1d ago

Honestly, I think you're overthinking it. Those cables just wear out.

elliotjenkins1d ago

Kinda reminds me of this old pair of earbuds I had back in college. They worked fine for like three years, then one day the left side just started crackling anytime I moved my head. Tried everything short of soldering them back together, but nope, they were just done. Sometimes things just give up the ghost.