Fastener Torque Specs

[Andrew Stephenson]

Hi all,

I was just wondering which fasteners you guys use a torque wrench for in your cars
and other vehicles you work on. One mechanic once told me he only uses a
torque wrench on head bolts. Which categories of fasteners do you torque, or
do you guys torque all of them?

Ta,

AJRS B)

Topic

[kevin gosselin]

Torquing wheel is a must as a shop can be reliable for it and it’s proven that over-torquing cause brake problem (warpage of rotor).

I use it also on intake gasket job and oil pan gasket job according to the material use for the gasket. Over-torquing those as well cause premature failure and there is no such thing as doing a job twice 1 year down the road.

[Andrew Stephenson]

Thank you for your reply. 🙂

[Dave]

I also use a torque wrench on small bolts and screws. Like a valve cover.

I once had a leaking thermostat housing. I kept turning turning the screws a quarter turn at a time trying to stop the leak. Eventually, I heard a “tink” when I stripped some threads.

Boy did I feel stupid!

I think a pound-inch torque wrench in quite valuable because unlike the bigger bolts, they are easier to strip.

And today with more and more aluminum, plastic and other cheap materials, torque wrenches are a must.

[Andrew Stephenson]

Ok thanks 🙂

[EricTheCarGuy]

Some people go overboard with worrying about torque. Head bolts and wheels as suggested are a great start. Some critical areas require that they be torqued a specific amount. Mostly engine and transmission components. As a technician you develop a ‘feel’ for how tight to make a fastener. Also, air tools and electric tools also help as they provide a consistent force when they are used. In fact, most vehicles are assembled with these tools at the factory. More info here.

[Dave]

I agree sir, but until you get that “feel”, you need a torque wrench.
Big things like 10mm on up (mostly)- OK, go and get “feel” because you can’t break anything i.e. “Snug”. Below that … It’s too easy to strip.

Not that I am saying you are wrong, but for us who aren’t so mechanically intuitive, it is a necessity.

[EricTheCarGuy]

I agree. It does take time to get that ‘feel’. Till then, use smaller tools rather than larger ones. Use 1/4″ tools on valve covers and such and avoid using 1/2″ tools on fasteners smaller than 17mm.

[Rob megee]

I torque any bolt that goes into aluminum. I also torque wheel lugs.

[Andrew Stephenson]

Thanks guys! 🙂

EDIT: I watched the videos, they’re pretty cool.

I watched the don’t make my life more difficult video, and it reminds me of my cousin.

My cousin’s friend put a turbocharger on my cousin’s stock Daihatsu Charade, which eventually caused catastrophic engine failure – the engine blew up.

And so I can only assume it got sent to the scrap yard.

So yes, I agree, if you don’t know what you’re doing when you pull your car apart you should learn first (in depth).

It also reminded me of myself, when I removed the header for my motorbike the gasket fell out, and I lost the gasket, because I didn’t even know what a gasket was back then, but luckily that was minor compared to putting in a turbo that the engine wasn’t designed for.

[Author]

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