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That hospital job in Phoenix taught me to never trust factory shims again
I was working on a Otis gen2 in Banner Desert Medical back in March. The car was leveling off by almost 3/8 inch every stop. Turns out the factory shim pack under the guide rails had shifted during a heat wave. Three hours of my life wasted because someone figured a nylon shim was fine for a 100 degree machine room. Has anyone else had a call where the factory "solution" caused the actual problem?
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wells.christopher4d ago
The bit about nylon creeping before it melts really hit home for me. I used to grab whatever shims were cheapest and figured close enough was fine for most jobs. That Phoenix story convinced me to stop cutting corners and just use metal shims in hot machine rooms.
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the_mia4d ago
The 120 degree machine room in Tucson last summer fried a plastic shim pack so bad it melted into a puddle under the rail. I mean, who thought cheap nylon could handle heat like that. Idk maybe it's just me but I'd rather spend an extra 20 bucks on metal shims than come back for a repeat call.
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lily_cooper4d ago
Read somewhere that nylon really starts breaking down around 160 degrees or so. Not like it just melts suddenly, it creeps and gets soft way before that. Tucson backrooms can get way hotter than that with all the equipment running. Plastic shims are fine for climate controlled machine rooms but in a desert summer they're basically just waiting to turn into a puddle. Kinda wild that anyone would spec nylon for that environment without checking the actual temp range.
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