An old timer told me I was using my torque wrench wrong - he was right

Been turning wrenches for about 8 years now, always followed the manual to the letter on torque specs. This retired fleet mechanic named Dave watched me torque down some head bolts on a Cummins ISX and just shook his head. He said I was going too slow and smooth, that you gotta run the torque wrench fast and steady in one motion or the readings are off. I thought he was full of crap since the click happens either way. Tried his method on the next job and actually checked with a different wrench - the fast pull got me within 2 ft-lbs consistency vs 6-8 ft-lbs variation my way. Now I do it his way every time but still feel stupid for not questioning my technique years ago. Anyone else had a stubborn habit that took a stranger calling you out to fix?

2 comments

2 Comments

webb.ben9d agoMost Upvoted

My buddy Eric had the exact same thing happen to him with a spark plug torque. He'd been a shade tree mechanic for years, always did them up with his torque wrench nice and slow. Then a guy at the parts store saw him doing it and told him he was probably overtorquing by a good 10 lbs because the drag was building up. Eric laughed it off, tried the fast pull method anyway, and sure enough, three of the plugs he'd done the slow way were tighter than the spec. He still talks about that guy like he saw the ghost of Smokey Yunick.

hayes.joel9d ago

My uncle Ray had a similar thing with his torque wrench on a 1987 F-150 he was rebuilding. He always did his final torquing on the head bolts using a smooth slow pull, and the engine ended up with a persistent tick that never went away until he sold the truck. Took a guy at the machine shop telling him to run it fast and consistent on the first pass, and suddenly the tick disappeared on the next rebuild.

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