Three years torquing lugnuts wrong until a wheel came off on the highway

I was doing oil changes and tire rotations at a shop in Austin for about 3 years. Always used the impact gun to zing lugnuts on, then called it good. Last month a customer came back with a wheel wobbling after a rotation I did. The studs were stretched and two of them snapped right off when I tried to re-torque. An old diesel mechanic walked over and showed me the torque spec was 100 ft-lbs, not whatever my gun was slamming them to. He made me use a torque stick and then a click wrench on every lug. I had no idea I was over-torquing by probably 40 ft-lbs that whole time. Anyone else learn the hard way that impacts and torque specs don't mix?

2 comments

2 Comments

ninal911mo ago

Three years torquing lugnuts wrong" sounds like you got lucky honestly.

miller.jason1mo ago

Guess I was torque-ally wrong, got lucky anyway.