How I finally solved loose conduit issues—steps that actually worked

I ran into this exact situation in my garage last weekend while I was tracing a circuit that kept tripping the GFCI. I found three different 1/2-inch flex runs that had pulled nearly an inch out of the steel boxes. The original installer must have skipped the anti-short bushings entirely because I didn't see a single "red devil" when I pulled the armor back. It's a miracle the vibration from the overhead door opener hadn't caused a fire yet given how frayed the THHN looked near those sharp edges.

I ended up replacing the old squeeze connectors with some Arlington snap-in fittings since the original zinc ones were stripped out and wouldn't grip the ribs of the conduit anymore. Getting those bushings in was a pain because the wire was pulled so tight, but I managed to get enough slack by loosening the next staple down the line. I also used a pair of Kleins to slightly flare the end of the armor so the bushing would seat better without popping out while I tightened the clamp. One thing I noticed is that if the conduit is under tension, just tightening the screw won't hold for long. I had to add a one-hole strap about six inches from the box to take the weight off the connector. Since doing that, everything feels solid and my multimeter shows a good ground path back to the panel. It’s a tedious fix when you have to do it for an entire room, but definitely better than a house fire.

You realy shoud verify that the locknut on the interior of the enclosure is acutally driven home with a flat-head and a mallet to ensure the tangs are biting into the metal, becasue a hand-tightened nut will eventually vibrate loose and compromise your entire equipment grounding conductor path regardless of how many straps you install. I’ve also found that many DIYers overlook the trade size fill capacity, wich leads to excessive internal friction that puts unnecessary mechanical stress on the connectors during thermal expansion cycles. Did you happen to verify if the FMC you’re working with is actually recognized as a grounding medium in that length, or are you pulling a dedicated copper ground?

Oh man, I am so glad I found this thread becasue the flex in my laundry room is doing this exact thing! I'm just starting to learn the ropes and didn't even know those red bushings existed untill now. Since I'm going to be fixing a bunch of these, do you guys reccomend getting one of those Roto-Split tools? I'm super nervous about using a hacksaw and hitting the copper by mistake while trying to trim the armor back. Is it a total game changer for a newbie or just a waste of money if I'm only doing one room?