the_nina•1mo agoMost Upvoted

That old timer's advice on injector torque saved me a headache

Last month I was working on a Cummins ISX and an old diesel vet I know told me I was overtightening the injector hold-downs. He said most guys crank them to 30 ft-lbs but the real spec is 18 with a 90 degree turn. I brushed it off until I snapped a bolt and had to helicoil the head. Now I always check the manual even if I think I know the spec. Has anyone else gotten burned by trusting your gut on torque specs?

2 comments

2 Comments

betty1361mo ago

Read a forum post where a guy stripped out his ISX head doing the same thing. Helicoil saved him too but he said the injector cup was always slightly loose after that.

patricia_green211mo ago

Yeah I get what you're saying but I'm gonna have to disagree a little bit. Torque wrenches go out of calibration all the time and trusting muscle memory over a cheap tool has saved me plenty of times when I didn't have a manual handy. That old timer probably knows his stuff from doing it wrong enough times to figure out what actually works.