My torque wrench lied to me on a Subaru head gasket job yesterday

I was torquing down the head bolts on a 2010 Outback and snapped one clean off at 55 ft-lbs when spec says 58. Turns out my Snap-on torque wrench was 12 ft-lbs over from sitting in my damp toolbox all winter. Has anyone else had their calibration drift from storage conditions like that?

2 comments

2 Comments

the_patricia17h ago

That '12 ft-lbs over' thing is wild, I read somewhere that torque wrenches can drift that bad just from temperature changes alone. Humidity in a toolbox really messes with the internal springs way more than people think. I had a buddy's Craftsman go off by almost 10 ft-lbs after a wet summer, so I always store mine in the house now with the setting dialed down to zero.

lily_sullivan8215h agoMost Upvoted

Yeah, dialing it down to zero is key. I've seen guys wreck their clickers by leaving them cranked up all the time, that constant tension kills the spring. And yeah, I keep mine in a sealed ammo can with a silica pack, never had an issue after a humid summer.