Old timer told me 'never trust a torque wrench that's been dropped' and I didn't listen

I was working on a PT6 engine at a little shop in northern Wisconsin about 5 years ago. This guy named Jerry, been doing this since the 70s, warned me not to use the shop's old Snap-on torque wrench because someone had knocked it off the workbench the day before. I figured it was fine since it looked straight and still clicked okay. Big mistake. I torqued down a cylinder base nut and it came out way under spec, maybe 40 ft-lbs instead of 55. When we ran the engine up, it started smoking from that cylinder area. Had to pull the whole jug back off and do a boroscope inspection. Nothing got ruined but it cost us a whole afternoon and a set of gaskets. Now I treat torque wrenches like they're made of glass. Has anyone else ever had a tool that seemed fine but was actually way off?

2 comments

2 Comments

kim19122d ago

You sure it wasn't just user error or a bad gasket? Torque wrenches are pretty tough, I've dropped mine a dozen times and it still checks fine against a beam style. Plus that old Snap-on stuff is built like a tank. Seems like Jerry was just being cranky and you had a bad luck coincidence. I'd be more suspicious of the cylinder base nut threads being dirty or the gasket being old than a simple drop.

paul34622d ago

Did you at least save the old gasket as a reminder to never trust anything Jerry says?