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Old timer said my torque wrench calibration was off, now I check it every month
Been doing diesel work for about 7 years and always thought my torque wrench was fine. Last spring a retired mechanic watched me torque down head bolts on an old 5.9 Cummins and said 'son, that wrench is lying to you.' I grabbed his Snap-on tester and sure enough I was 12 ft-lbs over on a 100 ft-lb setting. Changed my whole approach, now I take my main torque wrench to a shop in Nashville every 6 months for a $40 recalibration. Anybody else trust their tools too long and get burned?
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the_thea10d ago
Hold on a second, that story about snapping a bolt is kind of misleading. I mean, if your torque wrench is over-torquing by 12 ft-lbs, yeah, you're more likely to strip threads or yield the bolt, but snapping one clean off on a head is usually from something else, like not following a proper torque sequence or reusing old torque-to-yield bolts. The real risk with a bad calibration is messing up head gasket clamping force, which leads to leaks, not necessarily snapping a bolt in half. Idk, maybe it's just me but I've seen guys blame a bad wrench for what was actually a bad procedure. So checking calibration is smart, but don't fall for the scary story that a slightly-off wrench turns your engine block into confetti. Just something to keep in mind.
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